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AMC7834
SLAS972B – NOVEMBER 2014 – REVISED MARCH 2016
AMC7834 12-Bit Integrated Power-Amplifier Monitor and Control System with
Temperature, Current and Voltage Supervision Capabilities
•
•
•
•
•
•
•
•
Eight Monotonic 12-bit DACs With Programmable
Ranges
– Four Bipolar DACs:
–4 to 1 V, –5 to 0 V, and 0 to 5 V
– Four Unipolar DACs:
0 to 5 V, and 2.5 to 7.5 V
– High Current Drive Capability: up to ±10 mA
– Selectable Clamp Voltage
Multi-Channel 12-bit SAR ADC
– Four External Analog Inputs: 0 to 2.5 V Range
– Four Internal Inputs for Bipolar DAC Monitoring
– Programmable Out-of-Range Alarms
Four High-Side Current-Sense Amplifiers
– Common Mode Voltages: 4 to 60 V
– Optional Closed-Loop Drain-Current Controller
Operation
Temperature Sensing Capabilities
– Internal Temperature Sensor
– Two Remote Temperature-Diode Drivers
Internal 2.5 V Reference
Four General-Purpose I/O Ports (GPIOs)
Low-Power SPI-Compatible Serial Interface
– 4-Wire Mode, 1.7 to 3.6 V Operation
Operating Temperature Range: –40°C to +125°C
Available in a 56-Pin VQFN Package
The function integration and wide operatingtemperature range of the device make it suitable as
an all-in-one, low-cost, bias control-circuit for PAs
found in multi-channel RF communication systems.
The flexible DAC output ranges and wide common
mode voltage current sensors allow the device to be
used as a biasing solution for a large variety of
transistor technologies such as LDMOS, GaAs, and
GaN. The AMC7834 feature set is similarly beneficial
in general-purpose monitor and control systems.
For applications that require a different channelcount, additional features, or converter resolutions,
Texas Instruments offers a complete family of analog
monitor and control (AMC) products. For more
information, go to www.ti.com/amc.
Device Information(1)
PART NUMBER
AMC7834
PACKAGE
VQFN (56)
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
2 Applications
The AMC7834 device is a highly-integrated, lowpower, analog monitoring and control solution for
power-amplifier (PA) biasing capable of temperature,
current and voltage supervision.
4
Analog Inputs
MUX
4
Current Sense
ADC
Remote
Sensor
Driver
DAC
DAC
Temperature
Sensor
AUXDAC
AUXDAC
SPI
3 Description
AMC7834
2.5-V Reference
2 Remote
Temperature
Sensors
•
•
Communications Infrastructure:
– Cellular Base Stations
– Microwave Backhaul
– Optical Networks
General-Purpose Monitor and Control
Data Acquisition Systems
SPI
•
BODY SIZE (NOM)
8.00 mm × 8.00 mm
4 Bipolar
Analog Outputs
•
1
The device integrates a multi-channel, 12-bit analogto-digital converter (ADC); eight, 12-bit digital-toanalog converters (DAC); four high-side currentsense amplifiers that can be optionally set to operate
as part of four independent closed-loop drain-current
controllers; an accurate on-chip temperature sensor
and two remote temperature-sensor diode drivers;
four configurable general-purpose I/O ports (GPIOs);
and an accurate internal reference. The high level of
integration significantly reduces component count and
simplifies PA-biasing system designs.
4 Unipolar
Analog Outputs
1 Features
GPIO Control
4 GPIOs
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
AMC7834
SLAS972B – NOVEMBER 2014 – REVISED MARCH 2016
www.ti.com
Table of Contents
1
2
3
4
5
6
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
4
7
6.1
6.2
6.3
6.4
6.5
6.6
Absolute Maximum Ratings ...................................... 7
ESD Ratings.............................................................. 7
Recommended Operating Conditions....................... 8
Thermal Information .................................................. 8
Electrical Characteristics—DAC Specifications ........ 9
Electrical Characteristics—ADC, Current and
Temperature Sensor Specifications......................... 11
6.7 Electrical Characteristics—General Specifications . 12
6.8 Serial Interface Timing Requirements..................... 13
6.9 Switching Characteristics—DAC Specifications...... 14
6.10 Switching Characteristics—ADC, Current and
Temperature Sensor Specifications......................... 14
6.11 Switching Characteristics—General
Specifications ........................................................... 15
6.12 Typical Characteristics .......................................... 16
7
Detailed Description ............................................ 24
7.1
7.2
7.3
7.4
7.5
7.6
8
Overview .................................................................
Functional Block Diagram .......................................
Feature Description.................................................
Device Functional Modes .......................................
Programming...........................................................
Register Maps .........................................................
24
25
26
47
51
52
Application and Implementation ........................ 77
8.1 Application Information............................................ 77
8.2 Typical Application ................................................. 78
8.3 Initialization Set Up ................................................. 82
9 Power Supply Recommendations...................... 82
10 Layout................................................................... 82
10.1 Layout Guidelines ................................................. 82
10.2 Layout Example .................................................... 83
11 Device and Documentation Support ................. 85
11.1
11.2
11.3
11.4
11.5
Documentation Support ........................................
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
85
85
85
85
85
12 Mechanical, Packaging, and Orderable
Information ........................................................... 85
4 Revision History
Changes from Revision A (April 2015) to Revision B
Page
•
deleted text from the Description of pin 1 in the Pin Functions table " If unused the pin requires a 10 kΩ pullup
resistor to the IOVDD pin." ....................................................................................................................................................... 5
•
Added: Bipolar DACs in AVSS clamp mode To the Clamp Output Mode section of Electrical Characteristics—DAC
Specifications ....................................................................................................................................................................... 10
•
Deleted text from the Accuracy Test Conditions: "32 Samples Average" in Electrical Characteristics—ADC, Current
and Temperature Sensor Specifications ............................................................................................................................. 11
•
Added: AVDD alarm threshold to Electrical Characteristics—General Specifications .......................................................... 12
•
Changed the IIOVDD (Power-Mode 10) TYP value From: 1 µA To 1.75 µA in Electrical Characteristics—General
Specifications ....................................................................................................................................................................... 13
•
Changed the IIOVDD (Power-Mode 00) TYP value From: 0.2 µA To 1.75 µA in Electrical Characteristics—General
Specifications........................................................................................................................................................................ 13
•
Added Figure 29 .................................................................................................................................................................. 19
•
Changed Figure 45............................................................................................................................................................... 27
•
Added text to the itemized list in DAC Clamp Operation: "If the output buffer is inactive the clamp voltage is fixed to
AVSS.".................................................................................................................................................................................... 29
•
Added text to the end of DAC Clamp Operation: "Additionally, in the unique case..."......................................................... 29
•
Changed text in paragraph 1 of ADC Sequencing From: "The AMC7834 supports autonomous ADC conversion" To:
The AMC7834 supports autonomous and direct-mode conversions..." ............................................................................... 31
•
Change the paragraph: "Once the conversion cycle starts..." in ADC Sequencing ............................................................. 31
•
Deleted text from paragraph 3 of ADC Sequencing: "The first conversion sequence is reserved for calibration and
the corresponding ADC results should be ignored."............................................................................................................. 31
•
Added text to the last paragraph of ADC Sequencing: "In direct-mode conversion the DAV/ADC_RDY pin ... for
each channel group. "........................................................................................................................................................... 33
•
Added text to paragraph 3 of Drain Switch Control: The PA_ON signal state is also triggered by the AVDD
monitoring circuit................................................................................................................................................................... 39
2
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SLAS972B – NOVEMBER 2014 – REVISED MARCH 2016
Revision History (continued)
•
Changed text in two locations of paragraph 4 in Drain Switch Control: From: "AVSS" To: "AVDD and AVSS" ..................... 39
•
Added text to the last paragraph of Drain Switch Control: "The AVDD detection circuit is set to trigger the PA_ON
signal to the OFF state in response to an out of range event." ........................................................................................... 39
•
Added section: AVDD Detection Alarm ................................................................................................................................. 42
•
Changed text in the second paragraph of Open-Loop Mode From: "The current-sense amplifier outputs are
converted continuously by the device ADC.." To: "The current-sense amplifier outputs are converted by the device
ADC.." .................................................................................................................................................................................. 47
•
Changed 0x06 Default value From: 0000 To: 0001 in Table 9 ........................................................................................... 52
•
Changed R-00h To: R-01h in Bits 7:0 of Figure 69 ............................................................................................................. 54
•
Changed the Reset value From: 0000h To: 0001h in Table 13 .......................................................................................... 54
•
Changed Bit 12 of Table 15 From: Reserved To: CMODE ................................................................................................. 55
•
Changed Bit 10 of Table 18 From: 000: Invalid To: 000: 1 ................................................................................................. 56
•
Changed Bit 5-4 of Table 18 From: 00: Invalid To: 00: 1 .................................................................................................... 56
•
Changed Bit 3-2 of Table 18 From: 00: Invalid To: 00: 1 .................................................................................................... 57
•
Changed Bit 1-0 of Table 18 From: 00: Invalid To: 00: 1 .................................................................................................... 57
•
Changed General Status Register (address = 0x1F) [reset = 0x0000] ................................................................................ 67
•
Added text to item 2 of Initialization Procedure: A 250 µs POR delay occurs..." ................................................................ 82
Changes from Original (November 2014) to Revision A
•
Page
Release full version production data data sheet ................................................................................................................... 1
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SLAS972B – NOVEMBER 2014 – REVISED MARCH 2016
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5 Pin Configuration and Functions
43 AGND4
44 AVDD2
45 ADC4
46 ADC3
47 ADC2
48 ADC1
49 D2±
50 D2+
51 D1±
52 D1+
53 GPIO4
54 GPIO3
55 GPIO2
56 GPIO1
RTQ Package
56-Pin VQFN With Exposed Thermal Pad
Top View
DAV/ADC_RDY 1
42
REF_CMP
ALARMOUT 2
41
PAVDD
SLEEP1 3
40
PA_ON
SLEEP2 4
39
SENSE1+
RESET 5
38
SENSE1±
DACTRIG 6
37
SENSE2+
36
SENSE2±
35
AGND3
SDI 9
34
SENSE3+
SDO 10
33
SENSE3±
DGND 11
32
SENSE4+
IOVDD 12
31
SENSE4±
DVDD 13
30
VCLAMP1
AVCC 14
29
VCLAMP2
SCLK 7
4
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DAC4 28
DAC3 27
AVDD1 26
AVSS 25
DAC2 24
DAC1 23
AGND2 22
REF_IN 20
AUXDAC4 19
AUXDAC3 18
AGND1 17
AUXDAC2 16
AUXDAC1 15
CS 8
REF_OUT 21
Thermal
Pad
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SLAS972B – NOVEMBER 2014 – REVISED MARCH 2016
Pin Functions
PIN
TYPE
DESCRIPTION
NAME
NO.
ADC1
48
I
ADC2
47
I
ADC3
46
I
ADC4
45
I
AGND1
17
—
AGND2
22
—
AGND3
35
—
AGND4
43
—
ALARMOUT
2
O
AUXDAC1
15
O
AUXDAC2
16
O
AUXDAC3
18
O
AUXDAC4
19
O
AVCC
14
—
Positive analog power supply for the auxiliary DACs.
AVDD1
26
—
AVDD2
44
—
Analog supply voltage (4.5 V to 5.5 V). Connect the AVDD1 and AVDD2 pins to the same
potential (AVDD). These pins must have the same value as the DVDD pin.
AVSS
25
—
Lowest potential in the system. This pin is typically tied to a negative supply voltage. If all
the bipolar DACs are set to operate in positive output ranges can be connected to the
analog ground.
CS
8
I
Active low serial data enable. This input is the frame synchronization signal for the serial
data. When this signal goes low, it enables the serial interface input shift register.
D1+
52
I
Remote temperature sensor D1. This pin is a positive input when D1 is enabled. This pin
can be left unconnected if unused.
D1–
51
I
Remote temperature sensor D1. This pin is a negative input when D1 is enabled. This pin
can be left unconnected if unused. Pins D1– and D2– are internally shorted.
D2+
50
I
Remote temperature sensor D2. This pin is a positive input when D2 is enabled. This pin
can be left unconnected if unused.
D2–
49
I
Remote temperature sensor D2. This pin is a negative input when D2 is enabled. This pin
can be left unconnected if unused. Pins D1– and D2– are internally shorted.
DAC1
23
O
DAC2
24
O
DAC3
27
O
DAC4
28
O
DACTRIG
6
I
DAC trigger active low control input. When the DACTRIG pin is low, the contents of the
DAC data registers are transferred to the DAC active registers. The DAC outputs update
only after the DAC active registers have been loaded. This pin is only operational in open
loop current sensing mode.
Analog inputs channels. These channels are used for general monitoring. The input range
of these pins is 0 to Vref.
Analog ground. These pins are the ground reference point for all analog circuitry on the
device. Connect the AGND1, AGND2, AGND3, and AGND4 pins to the same potential
(AGND). Ideally, the analog and digital grounds should be at the same potential (GND) and
must not differ by more than ±0.3 V.
ALARMOUT is an open drain global alarm output. An external 10 kΩ pullup resistor to a
voltage no higher than AVDD is required. The ALARMOUT output polarity is defined through
the ALARMOUT-POLARITY bit in register 0x1B. The default polarity is active low.
Auxiliary DAC Outputs. The power-on-reset and clamp voltage for these DACs is always
AGND.
Bipolar DAC outputs 1 and 2. These DACs share the same range and clamp voltage.
Bipolar DAC outputs 3 and 4. These DACs share the same range and clamp voltage.
DAV/ADC_RDY
1
O
The DAV/ADC_RDY pin is in high-impedance mode by default and must be enabled
through the DAVPIN-EN bit in register 0x11 to access the DAV or ADC_RDY functionality.
DAV is an active low ADC synchronization signal. A 20 µs pulse (active low) on this pin is
used to indicate the end of a conversion sequence. Alternatively the pin can be set to
operate as ADC_RDY through the DAVPIN-SEL bit in register 0x11. ADC_RDY is an active
high synchronization signal used to indicate when the ADC is in the READY state.
DGND
11
—
Digital ground. This pin is the ground reference point for all digital circuitry on the device.
Ideally, the analog and digital grounds should be at the same potential (GND) and must not
differ by more than ±0.3 V.
DVDD
13
—
Digital supply voltage (4.5 V to 5.5 V). This pin must be the same value as the AVDD pins.
GPIO1
56
I/O
GPIO2
55
I/O
GPIO3
54
I/O
GPIO4
53
I/O
General-purpose digital I/Os. These pins are bidirectional open-drain, digital I/Os and
requires an external 10 kΩ pullup resistor to a voltage no higher than AVDD. If unused, the
GPIO pins should be connected to ground.
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Pin Functions (continued)
PIN
TYPE
DESCRIPTION
NAME
NO.
IOVDD
12
—
IO supply voltage (1.7 V to 3.6 V). This pin sets the I/O operating voltage and threshold
levels.
PAVDD
41
—
Power supply for the PA_ON control signal (4 V to 20 V).
PA_ON
40
O
PA_ON is a synchronization signal capable of driving an external PMOS switch and
controlling the flow of drain current to a power amplifier (PA) transistor. The PA_ON pin has
an internal 120 kΩ pull-up resistor to the PAVDD pin. The maximum output voltage is set by
the PAVDD pin and limited to 20 V. For drain voltages higher than 20 V, tying the PAVDD pin
to the AVDD pins and scaling the control signal externally is recommended. The PA_ON
signal state can be set through a register write but it can also be configured to trigger
automatically in the case of an ALARM event or when any of the SLEEP signals is
activated.
REF_CMP
42
I/O
Reference compensation capacitor connection. Connect a 4.7 μF capacitor between this
pin and the AGND4 pin for ADC reference compensation.
REF_IN
20
I
Reference input to the device. This pin can be connected to the REF_OUT pin to use the
device internal reference or alternatively to an external voltage reference source.
REF_OUT
21
O
Internal voltage reference output. Connect this pin directly to the REF_IN pin to operate the
device in internal reference mode. An external buffer amplifier with a high impedance input
is required to drive an external load. This pin can be left unconnected.
RESET
5
I
Active low reset input. Logic low on this pin causes the device to perform a hardware reset.
SCLK
7
I
Serial interface clock.
SDI
9
I
Serial interface data input. Data is clocked into the input shift register on each rising edge
of the SCLK pin.
SDO
10
O
Serial interface data output. The SDO pin is in high impedance when the CS pin is high.
Data is clocked out of the input shift register on each falling edge of the SCLK pin.
SENSE1+
39
I
Current sense 1 external sense resistor power connection
SENSE1–
38
I
Current sense 1 external sense resistor load connection
SENSE2+
37
I
Current sense 2 external sense resistor power connection
SENSE2–
36
I
Current sense 2 external sense resistor load connection
SENSE3+
34
I
Current sense 3 external sense resistor power connection
SENSE3–
33
I
Current sense 3 external sense resistor load connection
SENSE4+
32
I
Current sense 4 external sense resistor power connection
SENSE4–
31
I
Current sense 4 external sense resistor load connection
SLEEP1
3
I
Active high asynchronous power down digital input 1. The power down functions of this pin
are register configurable.
SLEEP2
4
I
Active high asynchronous power down digital input 2. The power down functions of this pin
are register configurable.
VCLAMP1
30
I
Power-on reset and clamp voltage control input for bipolar DACs 1 and 2. The resulting
power-on reset (POR) and clamp voltage value is given by Equation 1.
CLAMP = –3 × VCLAMP[1:2]
VCLAMP2
6
I
Power-on reset and clamp voltage control input for bipolar DACs 3 and 4. The resulting
POR and clamp voltage value is given by Equation 1.
—
The thermal pad is located on the bottom-side of the device package. The thermal pad
should be tied to the same potential as the AVSS pin for optimal thermal dissipation.
Alternatively, the thermal pad can be left unconnected.
29
Thermal Pad
(1)
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SLAS972B – NOVEMBER 2014 – REVISED MARCH 2016
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
Supply voltage
MIN
MAX
AVDD to GND
–0.3
6
DVDD to GND
–0.3
6
IOVDD to GND
–0.3
6
AVCC to GND
–0.3
13
–6
0.3
AVSS to GND
PAVDD to AVSS
–0.3
26
DGND to AGND
–0.3
0.3
ADC analog input voltage to GND
–0.3
AVDD + 0.3
Current sense input voltage to GND
–0.3
65
AVSS – 0.3
AVDD + 0.3
Auxiliary DAC outputs to GND
–0.3
AVCC + 0.3
VCLAMP1, VCLAMP2 inputs to GND
–0.3
AVDD + 0.3
D1+, D1–, D2+ and D2– to GND
–0.3
AVDD + 0.3
REF_CMP, REF_IN to GND
–0.3
AVDD + 0.3
REF_OUT to GND
–0.3
AVDD + 0.3
PA_ON to GND
–0.3
PAVDD + 0.3
CS, SCLK, SDI, DACTRIG, RESET, SLEEP1,
SLEEP2 and DAV/ADC_RDY to GND
–0.3
IOVDD + 0.3
SDO to GND
–0.3
IOVDD + 0.3
GPIOs, ALARMOUT to GND
–0.3
6
ADC analog input current
–10
10
REF_OUT output current
–0.3
0.3
Bipolar DAC outputs to GND
Pin voltage
Pin current
GPIOs, ALARMOUT sinking current
UNIT
V
V
mA
5
Operating temperature range
–40
125
°C
Junction temperature range, TJ max
–40
150
°C
Storage temperature, Tstg
–40
150
°C
(1)
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
6.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
±750
Charged device model (CDM), per JEDEC specification JESD22C101 (2)
±250
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
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6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
NOM
MAX
(1)
4.5
5
5.5
DVDD (1)
4.5
5
5.5
IOVDD
1.7
3.3
3.6
AVCC
4.5
5
12.5
AVSS (2)
–5.5
–5
0
PAVDD
4
5
20
Specified performance temperature
–40
25
105
°C
Operating temperature
–40
25
125
°C
AVDD
Supply voltage
(1)
(2)
UNIT
V
The value of the DVDD pin must be equal to that of the AVDD pins.
The value of the AVSS pin is only equal to AGND when all bipolar DACs are set to operate in positive voltage ranges.
6.4 Thermal Information
THERMAL METRIC (1) (2)
RTQ (VQFN)
56 PINS
RθJA
Junction-to-ambient thermal resistance
24.7
RθJC(top)
Junction-to-case (top) thermal resistance
7.9
RθJB
Junction-to-board thermal resistance
2.7
ψJT
Junction-to-top characterization parameter
0.2
ψJB
Junction-to-board characterization parameter
2.7
RθJC(bot)
Junction-to-case (bottom) thermal resistance
0.3
(1)
(2)
8
UNIT
°C/W
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
TI strongly recommends to solder the device thermal pad to a board plane connected to the AVSS pin.
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6.5 Electrical Characteristics—DAC Specifications
The electrical ratings specified in this section apply to all specifications in this document, unless otherwise noted. These
specifications are interpreted as conditions that do not degrade the device parametric or functional specifications for the life of
the product containing it. AVDD = DVDD = 5 V, AVCC = 5 V, AVSS = –5 V, IOVDD = 3.3 V, PAVDD = 5 V, AGND = DGND = 0 V,
external 2.5 V reference, DAC output range = 0 to 5 V for all DACs, no load on the DACs, current sense inputs common
mode at 48 V, TA = –40°C to +105°C
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
BIPOLAR DAC DC ACCURACY
Resolution
INL
DNL
TUE
Relative accuracy
Differential nonlinearity
Total unadjusted error
12
±0.3
±1
Measured by line passing through codes 040h and
FC0h. –4 to 1 V and –5 to 0 V ranges
±0.3
±1
Specified monotonic. Measured by line passing through
codes 040h and FC0h. 0 to 5 V range
±0.05
±1
Specified monotonic. Measured by line passing through
codes 040h and FC0h. –4 to 1 V and –5 to 0 V ranges
±0.05
±1
TA = 25°C, 0 to 5 V range
±1
±15
TA = 25°C, –4 to 1 V and –5 to 0 V ranges
±2
±15
±0.2
±10
mV
±2
±10
mV
TA = 25°C. Measured by line passing through codes
040h and FC0h. 0 to 5 V range
±0.02
±0.2
TA = 25°C. Measured by line passing through codes
040h and FC0h. –4 to 1 V and –5 to 0 V ranges
±0.02
±0.2
Offset error
TA = 25°C. Measured by line passing through codes
040h and FC0h. 0 to 5 V range
Zero-code error
TA = 25°C. Code 000h. –4 to 1 V and –5 to 0 V ranges.
AVSS = –5.5 V
Gain error
Bits
Measured by line passing through codes 040h and
FC0h. 0 to 5 V range
Offset temperature drift
0 to 5 V range
Zero-code temperature
drift
–4 to 1 V and –5 to 0 V ranges. AVSS = –5.5 V
Gain temperature drift
All output ranges
LSB
LSB
mV
%FSR
±1
ppm/°C
±1.5
ppm/°C
±1
ppm/°C
AUXILIARY DAC DC ACCURACY
Resolution
INL
DNL
TUE
Integral nonlinearity
Differential nonlinearity
Total unadjusted error
Offset error
Gain error
12
Bits
Measured by line passing through codes 040h and
FC0h. 0 to 5 V range
±0.5
±1.25
Measured by line passing through codes 040h and
FC0h. 2.5 to 7.5 V range. AVCC = 12 V
±0.5
±1.25
Specified monotonic. Measured by line passing through
codes 040h and FC0h. 0 to 5 V range
±0.05
±1
Specified monotonic. Measured by line passing through
codes 040h and FC0h. 2.5 to 7.5 V range. AVCC = 12 V
±0.05
±1
TA = 25°C. 0 to 5 V range
±2
±15
TA = 25°C. 2.5 to 7.5 V range. AVCC = 12 V
±2
±15
TA = 25°C. Measured by line passing through codes
040h and FC0h. 0 to 5 V range
±0.3
±10
TA = 25°C. Measured by line passing through codes
040h and FC0h. 2.5 to 7.5 V range. AVCC = 12 V
±1
±10
TA = 25°C. Measured by line passing through codes
040h and FC0h. 0 to 5 V range
±0.03
±0.2
TA = 25°C. Measured by line passing through codes
040h and FC0h. 2.5 to 7.5 V range. AVCC = 12 V
±0.03
±0.2
LSB
LSB
mV
mV
%FSR
Offset temperature drift
All output ranges
±1
ppm/°C
Gain temperature drift
All output ranges
±1
ppm/°C
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Electrical Characteristics—DAC Specifications (continued)
The electrical ratings specified in this section apply to all specifications in this document, unless otherwise noted. These
specifications are interpreted as conditions that do not degrade the device parametric or functional specifications for the life of
the product containing it. AVDD = DVDD = 5 V, AVCC = 5 V, AVSS = –5 V, IOVDD = 3.3 V, PAVDD = 5 V, AGND = DGND = 0 V,
external 2.5 V reference, DAC output range = 0 to 5 V for all DACs, no load on the DACs, current sense inputs common
mode at 48 V, TA = –40°C to +105°C
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
DAC OUTPUT CHARACTERISTICS
Bipolar DAC range (1)
Auxiliary DAC range (2)
DACn_range set to 00
–4
1
DACn_range set to 01
–5
0
DACn_range set to 10
–5
0
DACn_range set to 11
0
5
AUXDACn_range set to 0
0
5
AUXDACn_range set to 1
2.5
7.5
V
V
Short-circuit current
Bipolar DACs: Full-scale current shorted to AVSS or
AVDD
Auxiliary DACs: Full-scale current shorted to AGND or
AVCC
Load current (3)
Bipolar DACs: Source or sink with 300 mV headroom
from AVDD or AVSS, voltage drop < 25 mV
Auxiliary DACs: Source or sink with 300 mV headroom
from AVCC or AGND, voltage drop < 25 mV
Maximum capacitive
load (4)
All DAC outputs. RL = ∞
DC output impedance
All DAC outputs. Code set to 800h, ±10 mA
1
Ω
Glitch energy
All DAC outputs. Transition: Code 7FFh to 800h; 800h to
7FFh
1
nV-s
Output noise
45
mA
±10
mA
0
10
Auxiliary DACs. 1 kHz, code 800h
200
Bipolar DACs. 1 kHz, code 800h
100
Auxiliary DACs. Integrated noise from 0.1 Hz to 10 Hz,
code 800h
20
Bipolar DACs. Integrated noise from 0.1 Hz to 10 Hz,
code 800h
10
nF
nV/√Hz
µVPP
CLAMP OUTPUT MODE
VCLAMP [1:2] voltage
range
0
VCLAMP [1:2] input
current
Clamp output voltage
Clamp output current
Clamp pull-down
resistance
(1)
(2)
(3)
(4)
10
Bipolar DACs. Clamp voltage = –3 × VCLAMP[1:2]
AVSS
Auxiliary DACs
–AVSS / 3
V
±0.5
µA
0
V
AGND
Bipolar DACs. Source, sink, or both with 300-mV
headroom from AVSS, voltage drop < 25 mV
Auxiliary DACs. Measured to AGND
Bipolar DACs. VCLAMP buffers inactive (AVSS clamp
mode). Measured to AVSS
±10
mA
9
kΩ
550
Ω
The output voltage must not be greater than AVDD or lower than AVSS. A minimum of 100 mV headroom from AVDD is required.
The output voltage must not be greater than AVCC or lower than AGND. A minimum of 100 mV headroom from AVCC is required.
If all channels are simultaneously loaded, care must be taken to ensure the thermal conditions for the device are not exceeded.
To be sampled during initial release to ensure compliance; not subject to production testing.
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6.6 Electrical Characteristics—ADC, Current and Temperature Sensor Specifications
The electrical ratings specified in this section apply to all specifications in this document, unless otherwise noted. These
specifications are interpreted as conditions that do not degrade the device parametric or functional specifications for the life of
the product containing it. AVDD = DVDD = 5 V, AVCC = 5 V, AVSS = –5 V, IOVDD = 1.8 to 3.3 V, PAVDD = 5 V, AGND = DGND =
0 V, external 2.5 V reference, DAC output range = 0 to 5 V for all DACs, no load on the DACs, current sense inputs common
mode at 48 V, TA = –40°C to +105°C
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
±0.5
±1
LSB
±0.5
±1
LSB
±0.3
±4.5
LSB
EXTERNAL ANALOG INPUTS (ADC1, ADC2, ADC3 and ADC4)
Resolution
INL
Integral nonlinearity
DNL
Differential nonlinearity
12
Specified monotonic
Offset error
Offset error match
±1
Gain error
±0.3
Gain error match
LSB
±4
±1
Full-scale input range (1)
0
Input capacitance
DC-input leakage current
Bits
LSB
LSB
Vref
48
Unselected ADC input
V
pF
±2
µA
INTERNAL MONITORING INPUTS (BIPOLAR DAC-OUTPUT MONITORING)
Full scale input range (1)
Resolution
–5
LSB size
2.5
1.83
V
mV
CURRENT-SENSE INPUTS
Common mode voltage
Full scale sense voltage (1)
SENSEn+ – SENSEn-
Input resistance
Per current sense input terminal
4
60
V
0
200
mV
192
Gain accuracy
Input offset error
CS-FILTER[2:0] = 100
Common mode voltage = 4 V
CMRR
CS-FILTER[2:0] = 100
Resolution
LSB size
kΩ
±0.1%
±1%
±50
±500
µV
80
dB
48.83
µV
TEMPERATURE SENSOR: INTERNAL
Operating range (1) (2)
Specified monotonic over entire range.
Accuracy (2)
TJ = –40°C to 125°C
Resolution
LSB size
TJ = –40°C to 125°C
–55
125
°C
±3
°C
0.25
°C
TEMPERATURE SENSOR: EXTERNAL (USING 2N3906 EXTERNAL TRANSISTOR)
Operating range (1) (2)
(1)
(2)
–55
Accuracy (2)
RT-SET[2:0] = 011, CS-FILTER[2:0] = 100
TA = –40°C to 125°C, T(DIODE) = –40°C to 150°C
Resolution
LSB size
TA = –40°C to 125°C, T(DIODE) = –40°C to 150°C
150
°C
±3
°C
0.25
°C
Input range for all monitoring inputs must be met for accuracy specifications to apply.
Not tested during production. Specified by design and characterization.
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6.7 Electrical Characteristics—General Specifications
The electrical ratings specified in this section apply to all specifications in this document, unless otherwise noted. These
specifications are interpreted as conditions that do not degrade the device parametric or functional specifications for the life of
the product containing it. AVDD = DVDD = 5 V, AVCC = 5 V, AVSS = –5 V, IOVDD = 1.8 to 3.3 V, PAVDD = 5 V, AGND = DGND =
0 V, external 2.5 V reference, DAC output range = 0 to 5 V for all DACs, no load on the DACs, current sense inputs common
mode at 48 V, TA = –40°C to 105°C
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
100
µA
EXTERNAL REFERENCE INPUT
VREF_IN
Input voltage range
REF_IN pin
Input current
VREF_IN = 2.5 V
2.5
DAC reference buffer offset
TA = 25°C
±5
mV
ADC reference buffer offset
TA = 25°C
±5
mV
1
V
INTERNAL REFERENCE
Output voltage
TA = 25°C, REF_OUT pin
2.4925
Reference temperature
coefficient
Output voltage noise
1 kHz
Integrated noise from 0.1 Hz to 10 Hz
2.5
2.5075
10
35
V
ppm/°C
260
nV/√Hz
13
µVPP
PA_ON OUTPUT
PA_ON output voltage
PAVDD ≤ 20 V
AGND
PAVDD
V
SUPPLY ALARMS (1)
AVSS alarm threshold
–4.4
–4.1
–3.8
V
AVDD alarm threshold
3.4
3.9
4.4
V
DIGITAL LOGIC (1)
VIH
High-level input voltage
IOVDD = 1.7 V to 3.6 V
VIL
Low-level input voltage
IOVDD = 1.7 V to 3.6 V
Vhys
Hysteresis voltage
IOVDD = 1.7 V to 3.6 V
VOH
High-level output voltage
SDO and DAV/ADC_RDY. IOVDD = 1.7 V,
I(LOAD) = 1 mA
VOL
Low-level output voltage
IOVDD = 1.7 V to 3.6 V, I(LOAD) = –1 mA
0.7 ×
IOVDD
V
0.3 ×
IOVDD
0.1 ×
IOVDD
V
IOVDD –
0.4
V
High impedance leakage
High impedance output
capacitance
(1)
12
V
10
0.4
V
±0.5
µA
pF
Not tested during production. Specified by design and characterization.
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Electrical Characteristics—General Specifications (continued)
The electrical ratings specified in this section apply to all specifications in this document, unless otherwise noted. These
specifications are interpreted as conditions that do not degrade the device parametric or functional specifications for the life of
the product containing it. AVDD = DVDD = 5 V, AVCC = 5 V, AVSS = –5 V, IOVDD = 1.8 to 3.3 V, PAVDD = 5 V, AGND = DGND =
0 V, external 2.5 V reference, DAC output range = 0 to 5 V for all DACs, no load on the DACs, current sense inputs common
mode at 48 V, TA = –40°C to 105°C
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
10
12.5
mA
1.5
2
mA
POWER REQUIREMENTS
IAVDD
AVDD supply current
IAVCC
AVCC supply current
IAVSS
AVSS supply current
IDVDD
DVDD supply current
IIOVDD
IOVDD supply current
IPAVDD
PAVDD supply current
POWER-MODE = 10.
AVDD = DVDD = 5.5 V, AVCC = 5.5 V
PAVDD = 20 V, AVSS = –5.5 V, IOVDD = 3.6 V
All monitoring channels enabled
Bipolar DACs in –5 to 0 V range
Auxiliary DACs in 0 to 5 V range
All DACs at 800h code. PA_ON in "ON" state
–3.5
–2.5
mA
2.5
3
mA
1.75
2.5
µA
170
250
µA
120.5
mW
Power consumption
95
IAVDD
AVDD supply current
3.5
mA
IAVCC
AVCC supply current
0.2
mA
IAVSS
AVSS supply current
IDVDD
DVDD supply current
IIOVDD
IOVDD supply current
IPAVDD
PAVDD supply current
12
µA
Power consumption
45
mW
POWER-MODE = 00.
AVDD = DVDD = 5.5 V, AVCC = 5.5 V
PAVDD = 20 V, AVSS = –5.5 V, IOVDD = 3.6 V
All DACs in clamp mode at 0 V
PA_ON in "OFF" state
–2
mA
2.5
mA
1.75
µA
6.8 Serial Interface Timing Requirements (1) (2)
AVDD = DVDD = 5 V, AVCC = 5 V, AVSS = –5 V, PAVDD = 5 V, AGND = DGND = 0 V, external 2.5 V reference, DAC output
range = 0 to 5 V for all DACs, no load on the DACs, current sense inputs common mode at 48 V, TA = –40°C to +105°C
(unless otherwise noted)
IOVDD = 1.7 TO 2.7 V
IOVDD = 2.7 TO 3.6 V
MIN
MAX
MIN
MAX
10
0.2
15
UNIT
fSCLK
SCLK frequency
0.2
tp
SCLK period
100
66.67
ns
tPH
SCLK pulse width high
40
26
ns
tPL
SCLK pulse width low
40
26
ns
tsu
SDI setup
10
10
ns
th
SDI hold
10
10
t(ODZ)
SDO driven to tri-state
t(OZD)
SDO tri-state to driven
t(OD)
SDO output delay
tsu(CS)
CS setup
5
5
ns
th(CS)
CS hold
20
20
ns
t(IAG)
Inter-access gap
15
15
ns
(1)
(2)
See Figure 1 and Figure 2.
See Figure 2.
See Figure 1 and Figure 2
MHz
ns
0
15
0
10
ns
0
20
0
15
ns
0
20
0
15
ns
Specified by design and characterization. Not tested during production.
SDO loaded with 10 pF load capacitance for SDO timing specifications.
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6.9 Switching Characteristics—DAC Specifications
The electrical ratings specified in this section apply to all specifications in this document, unless otherwise noted. These
specifications are interpreted as conditions that do not degrade the device parametric or functional specifications for the life of
the product containing it. AVDD = DVDD = 5 V, AVCC = 5 V, AVSS = –5 V, IOVDD = 3.3 V, PAVDD = 5 V, AGND = DGND = 0 V,
external 2.5 V reference, DAC output range = 0 to 5 V for all DACs, no load on the DACs, current sense inputs common
mode at 48 V, TA = –40°C to +105°C
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
DAC OUTPUT CHARACTERISTICS
Output voltage settling
time
Transition: Code 400h to C00h to within ½ LSB.
RL= 2 kΩ, CL = 200 pF. All DAC outputs. All output
ranges
10
Slew rate
Transition: Code 400h to C00h, 10% to 90%.
RL= 2 kΩ, CL = 200 pF. All DAC outputs. All output
ranges
1.25
µs
V/µs
CLAMP OUTPUT MODE
(1)
Clamp shutdown delay (1)
All DAC outputs. RL = ∞, CL = 200 pF, clamp from 3.5 V
output, within 10% accuracy of active DAC output,
measured from SLEEP 0 to 1 transition
5
µs
Wake-up from clamp
delay (1)
All DAC outputs. RL = ∞, CL = 200 pF, wake-up to 3.5 V
output, within 10% accuracy of active DAC output,
measured from SLEEP 1 to 0 transition
5
µs
Not tested during production. Specified by design and characterization.
6.10 Switching Characteristics—ADC, Current and Temperature Sensor Specifications
The electrical ratings specified in this section apply to all specifications in this document, unless otherwise noted. These
specifications are interpreted as conditions that do not degrade the device parametric or functional specifications for the life of
the product containing it. AVDD = DVDD = 5 V, AVCC = 5 V, AVSS = –5 V, IOVDD = 1.8 to 3.3 V, PAVDD = 5 V, AGND = DGND =
0 V, external 2.5 V reference, DAC output range = 0 to 5 V for all DACs, no load on the DACs, current sense inputs common
mode at 48 V, TA = –40°C to +105°C
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
3.7
4
4.3
MHz
ADC INTERNAL OSCILLATOR
Internal oscillator frequency
EXTERNAL ANALOG INPUTS (ADC1, ADC2, ADC3 and ADC4)
Update time
All four external inputs enabled
Internal monitoring inputs disabled
1
ms
1
ms
200
µs
2
ms
8
ms
INTERNAL MONITORING INPUTS (BIPOLAR DAC-OUTPUT MONITORING)
Update time
All four internal monitoring inputs enabled
External analog inputs disabled
CURRENT-SENSE INPUTS
Update time
All four current sense inputs enabled
CS-FILTER[2:0] = 000
TEMPERATURE SENSOR: INTERNAL
Update time
Remote temperature sensors disabled
TEMPERATURE SENSOR: EXTERNAL (USING 2N3906 EXTERNAL TRANSISTOR)
Update time
14
Single external temperature sensor
Internal temperature sensor disabled
RT-SET[2:0] = 000
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6.11 Switching Characteristics—General Specifications
The electrical ratings specified in this section apply to all specifications in this document, unless otherwise noted. These
specifications are interpreted as conditions that do not degrade the device parametric or functional specifications for the life of
the product containing it. AVDD = DVDD = 5 V, AVCC = 5 V, AVSS = –5 V, IOVDD = 1.8 to 3.3 V, PAVDD = 5 V, AGND = DGND =
0 V, external 2.5 V reference, DAC output range = 0 to 5 V for all DACs, no load on the DACs, current sense inputs common
mode at 48 V, TA = –40°C to 105°C
PARAMETER
PA_ON OUTPUT
TEST CONDITIONS
MIN
PA_ON OFF state enable
PA_ON ON state enable
RESET REQUIREMENTS
MAX
UNIT
Measured from AVSS alarm event, CL = 1 nF
1
ms
Measured from SLEEP 0 to 1 transition, CL = 1
nF
1
ms
Measured from SLEEP 1 to 0 transition, CL = 1
nF
0.5
ms
250
µs
10
µs
(1)
Delay to normal operation from hardware reset
Reset delay
100
Delay to normal operation from software reset
Reset pulse width
(1)
TYP
(1)
20
ns
Not tested during production. Specified by design and characterization.
t(IAG)
th(CS)
tsu(CS)
CS
tp
tPL
SCLK
tPH
SDI
Bit 23
Bit 1
Bit 0
th
tsu
Figure 1. Serial Interface Write Timing Diagram
t(ODZ)
t(IAG)
th(CS)
tsu(CS)
CS
tP
tPL
SCLK
tPH
SDI
Bit 23
tsu
Bit 8
th
SDO
Bit 7
t(OZD)
Bit 0
t(OD)
Figure 2. Serial Interface Read Timing Diagram
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6.12 Typical Characteristics
6.12.1 Typical Characteristics: DAC
1.0
0.6
DAC 1
DAC 2
DAC 3
DAC 4
0.8
0.6
0.4
DNL (LSB)
0.4
INL (LSB)
1.0
DAC 1
DAC 2
DAC 3
DAC 4
0.8
0.2
0.0
-0.2
0.2
0.0
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
-1.0
-1.0
0
512
1024
1536
2048
2560
3072
3584
4096
Code
0
1.0
2048
2560
3072
3584
4096
C002
Figure 4. Bipolar DAC Differential Non-Linearity
1.0
DAC 1
DAC 2
DAC 3
DAC 4
0.8
0.6
DAC 1
DAC 2
DAC 3
DAC 4
0.8
0.6
0.4
DNL (LSB)
0.4
INL (LSB)
1536
DAC range = 0 to 5 V, AVDD = 5.5 V
Figure 3. Bipolar DAC Integral Non-Linearity
0.2
0.0
-0.2
0.2
0.0
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
-1.0
-1.0
0
512
1024
1536
2048
2560
3072
3584
4096
Code
0
0.8
0.6
0.6
0.4
0.4
DNL (LSB)
1.0
0.2
0.0
-0.2
-0.4
-0.8
-1.0
1536
2048
2560
3072
2560
3072
3584
4096
C004
3584
Code
AUXDAC 1
AUXDAC 2
AUXDAC 3
AUXDAC 4
0.2
0.0
-0.2
-0.4
AUXDAC 1
AUXDAC 2
AUXDAC 3
AUXDAC 4
-0.6
2048
Figure 6. Bipolar DAC Differential Non-Linearity
0.8
1024
1536
DAC range = –5 to 0 V, AVSS = –5.5 V
1.0
512
1024
Code
Figure 5. Bipolar DAC Integral Non-Linearity
0
512
C003
DAC range = –5 to 0 V, AVSS = –5.5 V
INL (LSB)
1024
Code
DAC range = 0 to 5 V, AVDD = 5.5 V
-0.6
-0.8
-1.0
4096
0
512
1024
1536
2048
2560
3072
Code
C005
DAC range = 0 to 5 V, AVCC = 5.5 V
3584
4096
C006
DAC range = 0 to 5 V, AVCC = 5.5 V
Figure 7. Auxiliary DAC Integral Non-Linearity
16
512
C001
Figure 8. Auxiliary DAC Differential Non-Linearity
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Typical Characteristics: DAC (continued)
1.0
0.8
0.6
AUXDAC 1
AUXDAC 2
AUXDAC 3
AUXDAC 4
0.8
0.6
0.4
DNL (LSB)
0.4
INL (LSB)
1.0
AUXDAC 1
AUXDAC 2
AUXDAC 3
AUXDAC 4
0.2
0.0
-0.2
0.2
0.0
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
-1.0
-1.0
0
512
1024
1536
2048
2560
3072
3584
0
4096
Code
512
C007
2048
2560
3072
3584
4096
C008
DAC range = 2.5 to 7.5 V, AVCC = 12 V
Figure 10. Auxiliary DAC Differential Non-Linearity
Figure 9. Auxiliary DAC Integral Non-Linearity
1.0
1.0
INL MAX
0.8
DNL MAX
0.8
INL MIN
0.6
DNL MIN
0.6
0.4
0.4
DNL (LSB)
INL (LSB)
1536
Code
DAC range = 2.5 to 7.5 V, AVCC = 12 V
0.2
0.0
-0.2
0.2
0.0
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
-1.0
-1.0
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
C009
DAC range = 0 to 5 V, AVDD = 5.5 V
C010
DAC range = 0 to 5 V, AVDD = 5.5 V
Figure 11. Bipolar DAC INL vs Temperature
Figure 12. Bipolar DAC DNL vs Temperature
1.0
1.0
INL MAX
0.8
DNL MAX
0.8
INL MIN
0.6
DNL MIN
0.6
0.4
0.4
DNL (LSB)
INL (LSB)
1024
0.2
0.0
-0.2
0.2
0.0
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
-1.0
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
-1.0
±40 ±25 ±10
C011
20
35
50
65
80
95
110 125
TA (ƒC)
C012
DAC range = –5 to 0 V, AVSS = –5.5 V
DAC range = –5 to 0 V, AVSS = –5.5 V
Figure 13. Bipolar DAC INL vs Temperature
5
Figure 14. Bipolar DAC DNL vs Temperature
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Typical Characteristics: DAC (continued)
1.0
DNL MAX
0.8
INL MIN
0.6
0.6
0.4
0.4
DNL (LSB)
INL (LSB)
1.0
INL MAX
0.8
0.2
0.0
-0.2
0.2
0.0
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
-1.0
DNL MIN
-1.0
5
±40 ±25 ±10
20
35
50
65
80
95
110 125
TA (ƒC)
±40 ±25 ±10
1.0
50
65
80
95
110 125
C014
Figure 16. Auxiliary DAC DNL vs Temperature
1.0
INL MAX
0.8
DNL MAX
DNL MIN
0.8
INL MIN
0.6
0.6
0.4
0.4
DNL (LSB)
INL (LSB)
35
DAC range = 0 to 5 V, AVCC = 5.5 V
Figure 15. Auxiliary DAC INL vs Temperature
0.2
0.0
-0.2
0.2
0.0
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
-1.0
-1.0
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
C015
DAC range = 2.5 to 7.5 V, AVCC = 12 V
C016
DAC range = 2.5 to 7.5 V, AVCC = 12 V
Figure 17. Auxiliary DAC INL vs Temperature
Figure 18. Auxiliary DAC DNL vs Temperature
10
10
8
8
6
6
Zero Code Error (mV)
Offset Error (mV)
20
TA (ƒC)
DAC range = 0 to 5 V, AVCC = 5.5 V
4
2
0
±2
±4
-5 to 0 V
-4 to 1 V
4
2
0
±2
±4
±6
±6
±8
±8
±10
±10
±40 ±25 ±10
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
5
20
35
50
TA (ƒC)
65
80
95
110 125
C018
C017
AVSS = –5.5 V
DAC range = 0 to 5 V
Figure 19. Bipolar DAC Offset Error vs Temperature
18
5
C013
Figure 20. Bipolar DAC Zero Code Error vs Temperature
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Typical Characteristics: DAC (continued)
0.20
0.12
4.5
4.0
0.08
DAC Output (V)
Gain Error (%FSR)
5.0
0 to 5 V
-5 to 0 V
-4 to 1 V
0.16
0.04
0.00
-0.04
-0.08
3.5
3.0
2.5
2.0
1.5
-0.12
1.0
-0.16
0.5
-0.20
0.0
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
±60 ±50 ±40 ±30 ±20 ±10
AVDD = 5.5 V, AVSS = –5.5 V
20
30
40
50
60
C020
Figure 22. DAC Output Voltage vs Load Current
5.000
0.50
4.950
0.40
DAC Output (V)
DAC Output (V)
10
DAC range = 0 to 5 V, Code 0x800
Figure 21. Bipolar DAC Gain Error vs Temperature
4.900
4.850
4.800
0.30
0.20
0.10
4.750
0.00
0
1
2
3
4
5
6
7
8
±15 ±14 ±13 ±12 ±11 ±10 ±9 ±8 ±7 ±6 ±5 ±4 ±3 ±2 ±1 0
9 10 11 12 13 14 15
Load Current (mA)
Load Current (mA)
C021
DAC range = 0 to 5 V, Code 0xFFF
C022
DAC range = 0 to 5 V, Code 0x000, AVSS = 0 V
Figure 23. DAC Source Current
Figure 24. DAC Sink Current
50
10
100pF
200pF
1nF
10nF
40
30
8
6
20
Output Noise (uV)
DAC Ouput Error (mV)
0
Loading Current (mA)
C019
10
0
-10
-20
4
2
0
±2
±4
-30
±6
-40
±8
-50
AUXDAC
DAC
±10
0
5
10
15
20
25
Time ( s)
30
0
Code 0x000 to 0xFFF to within 0.5% of final value
Figure 25. DAC Settling Time
2
4
6
8
10
12
14
16
18
Time (s)
C023
20
C024
Code 0x800
Figure 26. DAC Output Noise, 0.1 Hz to 10 Hz
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Typical Characteristics: DAC (continued)
1000
10.0
7.5
5.0
2.5
Voltage (V)
2XWSXW 1RLVH Q9 ¥+]
800
600
400
0.0
-2.5
PA_ON
-5.0
200
DAC OUT
-7.5
AVSS
0
1
10
100
1k
10k
100k
Frequency (Hz)
1M
-10.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Time (ms)
C025
Bipolar DAC, Code 0x800
C039
DAC range: –5 to 0 V, Code 0x800
Figure 27. DAC Noise Voltage vs Frequency
Figure 28. PA_ON Response to AVSS Supply Collapse
10.0
15
7.5
AVDD
PA_ON
DAC OUT
AVSS
10
5
2.5
Voltage (V)
Voltage (V)
5.0
0.0
±2.5
0
±5
±5.0
AVDD
AVCC
PA_ON
±10
±7.5
±10.0
±0.2
±15
±0.1
0.0
0.1
0.2
0.3
0.4
Time (ms)
0.5
-0.5
1.0
1.5
2.0
2.5
3.0
C040
DAC range: –4 to 1 V, VCLAMP[1:2] = 4/3 V
Figure 29. Response to AVDD Supply Collapse
20
0.5
Time (ms)
C041
DAC range: –4 to 1 V, Code 0x800
0.0
AVSS
IOVDD
DAC OUT
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Figure 30. DAC Power On
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1.0
1.0
0.8
0.8
0.6
0.6
0.4
0.4
DNL (LSB)
INL (LSB)
6.12.2 Typical Characteristics: ADC
0.2
0.0
-0.2
0.2
0.0
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
-1.0
-1.0
0
512
1024
1536
2048
2560
3072
3584
0
4096
Code
512
1024
C026
2560
3072
3584
4096
C027
Figure 32. ADC DNL
1.0
1.0
MAX INL
0.8
MAX DNL
0.8
MIN INL
0.6
MIN DNL
0.6
0.4
DNL (LSB)
0.4
INL (LSB)
2048
Code
Figure 31. ADC INL
0.2
0.0
-0.2
0.2
0.0
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
-1.0
-1.0
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
C028
Figure 33. ADC INL vs Temperature
C029
Figure 34. ADC DNL vs Temperature
2.0
1.0
1.6
0.8
1.2
0.6
0.8
0.4
Gain Error (LSB)
Offset Error (LSB)
1536
0.4
0.0
-0.4
-0.8
0.2
0.0
-0.2
-0.4
-1.2
-0.6
-1.6
-0.8
-2.0
-1.0
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
±40 ±25 ±10
Figure 35. ADC Offset Error vs Temperature
5
20
35
50
65
80
95
110 125
TA (ƒC)
C030
C031
Figure 36. ADC Gain Error vs Temperature
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0.5
0.5
0.4
0.4
0.3
0.3
0.2
0.2
Gain Error (%)
Offset (mV)
6.12.3 Typical Characteristics: Current Sense
0.1
0.0
-0.1
0.1
0.0
-0.1
-0.2
-0.2
-0.3
-0.3
-0.4
-0.4
-0.5
-0.5
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
±40 ±25 ±10
0
0.8
-10
0.6
-20
0.4
-30
CMRR (dB)
Gain Error (%)
50
65
80
95
110 125
C033
Figure 38. Current Sense Gain Error vs Temperature
1.0
0.2
0.0
-0.2
-40
-50
-60
-0.4
-70
-0.6
-80
-0.8
-90
-1.0
-100
12 16 20 24 28 32 36 40 44 48 52 56 60
Common Mode (V)
35
VCM = 28 V
Figure 37. Current Sense Offset Voltage vs Temperature
8
20
TA (ƒC)
VCM = 28 V, VSENSE = 0 V, CS-FILTER[2:0] = 100
4
5
C032
10
100
1k
10k
100k
1M
Frequency (Hz)
C034
C035
CS-FILTER[2:0] = 100
Figure 39. Current Sense Gain Error vs Common-Mode
Voltage
22
Figure 40. Current Sense CMRR vs Frequency
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6.12.4 Typical Characteristics: Temperature Sensor
Remote Temperature Sensor Error (ƒC)
Local Temperature Sensor Error (ƒC)
3.0
2.5
2.0
1.5
1.0
0.5
0.0
±0.5
±1.0
±1.5
±2.0
±2.5
±3.0
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
3.0
2.5
2.0
1.5
1.0
0.5
0.0
±0.5
±1.0
±1.5
±2.0
±2.5
±3.0
±40 ±25 ±10
5
20
35
50
65
80
95
110 125
TA (ƒC)
C036
10 units
C037
10 units, T(DIODE) = 25°C, RT-SET[2:0] = 011
Figure 41. Local Temperature Sensor Error vs
Temperature
Figure 42. Remote Temperature Sensor Error vs
Temperature
6.12.5 Typical Characteristics: Reference
2.5075
REF_OUT Voltage (V)
2.5050
2.5025
2.5000
2.4975
2.4950
2.4925
±40 ±25 ±10
5
20
35
50
65
80
TA (ƒC)
95
110 125
C038
10 units
Figure 43. Reference Output Voltage vs Temperature
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7 Detailed Description
7.1 Overview
The AMC7834 is a highly-integrated analog-monitoring and control solution for power-amplifier (PA) biasing
capable of current, temperature, and voltage supervision. The AMC7834 integrates the following features:
• Eight, 12-bit digital-to-analog converters (DACs) with programmable output ranges
– Four bipolar DACs with selectable output ranges: –4 to 1 V, –5 to 0 V, and 0 to 5 V
– The clamp and power-on-reset (POR) voltage for these DACs is pin-configurable.
– Four auxiliary DACs with selectable output ranges: 0 to 5 V and 2.5 to 7.5 V
– The clamp and POR voltage for these DACs is fixed to AGND.
– The DACs can be configured to clamp automatically upon detection of an alarm event.
• A multi-channel, 12-bit analog-to-digital converter (ADC) for voltage, temperature, and current sensing
– Four external analog inputs: 0 to 2.5 V
– Four internal inputs for monitoring the bipolar DAC outputs
– Programmable threshold detectors
• Four high-side current-sense amplifiers
– Common mode voltages from 4 V up to 60 V
– The current sensors can optionally be set to operate as part of four independent closed-loop drain-current
controllers
• Temperature sensing capabilities
– On-chip temperature sensor
– Two remote temperature sensor diode drivers
• Four general-purpose I/O (GPIO) ports
• Internal 2.5 V precision reference
– The device can operate from an internal reference. Alternatively an external reference can be used.
• Four-wire SPI-compatible interface supporting 1.7 to 3.6 V operation
The AMC7834 device is characterized for operation over the temperature range of –40ºC to 125ºC which makes
the device suitable for harsh-condition applications. The device is available in an 8-mm × 8-mm 56-pin VQFN
PowerPAD package.
The AMC7834 high-integration makes it an ideal all-in-one, low-cost, bias-control circuit for the PAs found in
multi-channel RF communication systems. The flexible DAC output ranges allow the device to be used as a
biasing solution for a large variety of transistor technologies such as LDMOS, GaAs, and GaN. The AMC7834
feature set is similarly beneficial in general-purpose monitor and control systems.
24
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REF_CMP
ADC1
Reference
(2.5 V)
ADC2
ADC3
REF_IN
ADC4
Bipolar DAC
Outputs
Conditioning and
Sensing
ADCINT1
ADCINT2
ADCINT3
ADCINT4
ADC
Trigger
DAC
Trigger
CS1
SENSE1±
DAC-2
12-b
SENSE2+
CS2
SENSE2±
DAC-3
12-b
ADC
12-b
SENSE3+
CS3
SENSE3±
DAC-4
12-b
SENSE4+
DAC1
DAC2
DAC3
BIPOLAR DAC OUTPUTS
DAC-1
12-b
SENSE1+
CURRENT SENSE
REF_OUT
Constant Current Mode Engine
ANALOG INPUTS
7.2 Functional Block Diagram
DAC4
CS4
SENSE4±
Temperature
Sensor
LT
VCLAMP1
VCLAMP2
SLEEP1
SLEEP2
DAC
Shutdown
D1+
Remote
temperature
driver
D2+
RT2
D2±
ALARMOUT
DVDD
Control, Limits, Status
Registers
Out-of-Limits
Alarm
Synchronization
Logic
GPIO Control
AUXDAC1
12-b
AUXDAC1
AUXDAC2
12-b
AUXDAC2
AUXDAC3
12-b
AUXDAC3
AUXDAC4
12-b
AUXDAC4
AUXILIARY DAC OUTPUTS
TEMP SENSORS
RT1
D1±
Serial Interface
Register and Control
(SPI)
DGND
AGND4
AGND3
AGND2
PAVDD
AGND1
AVCC
AVDD2
AVSS
AVDD1
SDO
CS
SDI
SCLK
GPIO4
GPIO3
GPIO2
GPIO1
RESET
PA_ON
DACTRIG
DAV/ADC_RDY
IOVDD
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7.3 Feature Description
7.3.1 Digital-to-Analog Converters (DACs)
The AMC7834 device features an analog-control system centered on eight, 12-bit DACs that can operate from
an external reference or the device internal reference. Each DAC core consists of a string DAC and an outputvoltage buffer.
The resistor-string structure consists of a series of resistors, each with a value of R. The code loaded to the DAC
determines at which node on the string the voltage is tapped off to be fed into the output amplifier. The voltage is
tapped off by closing one of the switches connecting the string to the amplifier (see Figure 44). The resistor string
architecture has inherent monotonicity, voltage output, and low glitch. The resistor string architecture is also
linear because all the resistors are of equal value.
R
R
R
To Output
Amplifier
R
R
Figure 44. DAC Resistor String
26
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Feature Description (continued)
7.3.1.1 DAC Configuration
The eight DACs are split into bipolar and auxiliary outputs based on their output range and clamping capabilities
as listed in Table 1. After power-on or a reset event the DAC outputs are directed automatically to the
corresponding clamp value and all DAC buffer and active registers are set to the default values.
Table 1. DAC Group Configuration
DAC
TYPE
OUTPUT RANGES
Bipolar
0 to 5 V
–4 to 1 V
–5 to 0 V
Auxiliary
0 to 5 V
2.5 to 7.5 V
DAC1 and DAC2
DAC3 and DAC4
CLAMP VOLTAGE
–3 × VCLAMP1 or
AVSS
–3 × VCLAMP2 or
AVSS
POWER SUPPLY
RANGE
CLOSED LOOP
OPERATION
CAPABLE?
AVSS to AVDD
Yes
AGND to AVCC
No
AUXDAC1
AUXDAC2
AUXDAC3
AGND
AUXDAC4
7.3.1.1.1 Bipolar DACs (DAC1, DAC2, DAC3, and DAC4)
The bipolar DACs are configured as DAC pairs (DAC1-DAC2 and DAC3-DAC4). The output range for each
bipolar DAC pair can be configured through the DAC Range register (address 0x16) to one of the following: 0 to
5 V, –5 to 0 V, or –4 to 1 V. The POR and clamp value of each DAC pair is set by the pins VCLAMP1 (for the
DAC1-DAC2 pair) and VCLAMP2 (for the DAC3-DAC4 pair) to any voltage between AVSS and 0 V during normal
operation. If AVDD falls outside the device specified operating range the bipolar DACs enter the special AVSS
clamp mode and their outputs are set to AVSS. The full-scale output range of the bipolar DACs is limited by the
power supplies, AVDD and AVSS.
The bipolar DACs operate as standalone DACs when the AMC7834 is set in open-loop mode (LOOP-EN bit set
to 0 in register 0x10). Figure 45 shows a high level block diagram of each bipolar DAC when operating in openloop mode.
AVDD
Serial Interface
DAC Data Register
WRITE
READ
DAC
Buffer Register
DAC
Active Register
0
Resistor String
DAC Trigger
(synchronous mode)
0x000
VOUT
DAC output
1
CLAMP MODE
AVSS CLAMP MODE
G = í3
(asynchronous mode)
DAC
Output
Configuration
VCLAMP[1,2]
AVSS
Figure 45. Bipolar DAC Block Diagram — Open Loop Operation
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Alternatively, with the AMC7834 set in closed-loop mode (LOOP-EN bit set to 1 in register 0x10) each bipolar
DAC output updates automatically in response to one of the four current sensors in the device (see the ClosedLoop Mode section). In closed-loop mode the AMC7834 bipolar DACs operate as four autonomous closed-loop
current controllers.
The DAC upper threshold registers (address 0x4E through 0x4F) sets an upper output limit other than full-scale
for the bipolar DACs when operating in closed-loop mode. The upper threshold feature can be used to limit the
maximum output voltage for each bipolar DAC. When a closed-loop controller attempts to set its bipolar DAC to a
value exceeding the corresponding DAC upper threshold register, the DAC is updated with the threshold code
instead.
7.3.1.1.2 Auxiliary DACs (AUXDAC1, AUXDAC2, AUXDAC3, and AUXDAC4)
The output range for each auxiliary DAC can be independently set through the DAC Range register (address
0x16) to either 0 to 5 V or 2.5 to 7.5 V. The POR and clamp value of each of the auxiliary DACs is fixed to
AGND. The maximum and minimum outputs from these DACs cannot exceed AVCC or be lower than AGND,
respectively. Figure 46 shows a high level block diagram of each auxiliary DAC.
AVCC
Serial Interface DAC Data Register
WRITE
READ
DAC
Buffer
Register
DAC
Active
Register
0x000
DAC Trigger
(synchronous
mode)
0
Resistor String
1
DAC
Output
Range
Configuration
DAC
output
VO
CLAMP MODE
CLAMP MODE
(asynchronous mode)
AGND
Figure 46. Auxiliary DAC Block Diagram
7.3.1.2 DAC Register Structure
The input data of the DACs is written to the individual DAC data registers (address 0x30 through 0x37) in straight
binary format for all output ranges (see Table 2).
Table 2. DAC Data Format
DIGITAL CODE
28
DAC OUTPUT VOLTAGE (V)
0 TO 5 V RANGE
2.5 TO 7.5 V RANGE
–4 TO 1 V RANGE
0000 0000 0000
0
2.5
–4
–5 TO 0 V RANGE
–5
0000 0000 0001
0.00122
2.50122
–3.99878
–4.99878
1000 0000 0000
2.5
5
–1.5
–2.5
1111 1111 1110
4.99756
7.49756
0.99756
–0.00244
1111 1111 1111
4.99878
7.49878
0.99878
–0.00122
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Data written to the DAC data registers is initially stored in the DAC buffer registers. The transfer of data from the
DAC buffer registers to the active registers can be set to occur immediately (asynchronous mode) or initiated by
a DAC trigger signal (synchronous mode). When the active registers are updated, the DAC outputs change to the
new values. When the host reads from a DAC data register, the value held in the DAC active register is returned
(not the value held in the buffer register).
The update mode of the DACs is determined by the DAC sync register (address 0x15). In asynchronous mode, a
write to a DAC data register results in an immediate update of the DAC active register and the corresponding
output. In synchronous mode, writing to a DAC data register does not automatically update the DAC output.
Instead, the update occurs only after a DAC trigger event. A DAC trigger is generated either through the DACTRIG bit in the DAC and ADC trigger register (address 0x1C) or by the DACTRIG pin. By setting the
synchronization properly, several DACs can be updated simultaneously.
7.3.1.3 DAC Clamp Operation
Each DAC can be set to a clamp mode using either hardware or software. When a DAC goes to clamp mode,
the DAC output is immediately set to the corresponding clamp voltage. However, clamping does not clear the
DAC buffer or active registers making it possible to return to the same voltage being output before the clamp
event was issued. The DAC data registers can be updated while the DACs are in clamp mode allowing the DACs
to output new values upon return to normal operation. When the DACs exit clamp mode, the DACs are
immediately loaded with the data in the DAC active registers and the output is set back to the corresponding
level to restore operation regardless of the DAC synchronization setting.
The clamp voltage is dependent on the DAC output:
•
•
•
DAC1 and DAC2: Clamp voltage is set by the voltage at pin VCLAMP1 and is equal to –3 × VCLAMP1 during
normal operation. In the special AVSS clamp mode the clamp voltage for DAC1 and DAC2 is fixed to AVSS.
DAC3 and DAC4: Clamp voltage is set by the voltage at pin VCLAMP2 and is equal to –3 × VCLAMP2 during
normal operation. In the special AVSS clamp mode the clamp voltage for DAC3 and DAC4 is fixed to AVSS.
AUXDAC1 through AUXDAC4: The clamp voltage for each of the auxiliary DACs is fixed to AGND.
The clamp register (address 0x17) allows clamping of the DACs through software. The DAC1-DAC2 pair, DAC3DAC4 pair, and each auxiliary DAC has a corresponding DAC clamp bit. Setting this bit to 1 forces the
corresponding DAC pair or individual auxiliary DAC to enter clamp mode. Clearing the bit to 0 restores normal
operation.
Additionally, in the unique case of the AVDD supply falling outside its specified operating range the bipolar DACs
enter the alternative AVSS clamp mode. With the AVDD supply outside of the valid operating range the bipolar
DAC output buffers become inactive thus creating the potential for unexpected output voltages. The AVSS clamp
mode prevents this condition by setting all bipolar DAC outputs to AVSS through a resistive path.
NOTE
If the DAC or DAC pair is forced to clamp by one of the SLEEP pins, write commands to
the corresponding DAC clamp bit are ignored.
The DACs can also be forced to clamp through the SLEEP1 and SLEEP2 pins. When either pin goes high, the
corresponding DAC pair and auxiliary DAC associated with each pin are forced into clamp mode. The SLEEP1
register (address 0x18) determines which DACs are forced to clamp when the SLEEP1 pin goes high. The
register contains one bit for each DAC pair (DAC1-DAC2 and DAC3-DAC4) and each auxiliary DAC. Likewise,
the SLEEP2 register (address 0x19) determines which DACs go into clamp when the SLEEP2 pin goes high. In
addition to forcing the DACs into clamp mode, the SLEEP1 and SLEEP2 pin and registers allow control of the
PA_ON pin.
Although a high state on the SLEEP pins force the associated DACs to clamp immediately, returning to a low
state does not necessarily force the DAC to return to normal operation. If the end application requires the DACs
to exit clamp mode in a particular sequence, this sequence can be controlled by the SNOOZE bits in the
SLEEP1 and SLEEP2 registers. When a SNOOZE bit is set to 1, bringing a DAC back to normal operation
requires the SLEEP pin to return to a low state first, followed by a write to the DAC clamp register (address 0x17)
to clear the clamp condition. If the SNOOZE bit is cleared to 0, setting the SLEEP pin to a low state immediately
clears the clamp condition and returns the DAC to normal operation without the need for any register writes.
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The DACs can be forced to enter clamp mode by the alarm events controlling the ALARMOUT pin. The
ALARMOUT clamp register (address 0x1A) selects the DAC or DAC pairs that enter clamp mode when the
ALARMOUT pin goes active. Restoring the ALARMOUT pin does not automatically return the DAC or DAC pairs
back to normal operation.
7.3.2 Analog-to-Digital Converter (ADC)
The AMC7834 device features a monitoring system centered on a 12-bit successive approximation register
(SAR) ADC fronted by a 15-channel multiplexer and an on-chip track-and-hold circuit. The monitoring system is
capable of sensing up to 4 external inputs (0 to 2.5 V range), 4 internal inputs (bipolar DAC monitoring), 4
current-sense amplifier inputs, 2 remote temperature sensors, and an internal analog-temperature sensor.
The ADC can operate from either an external 2.5 V reference or the device internal reference (Vref). The ADC
input range is 0 V to Vref. All ADC inputs are internally mapped to this range. The ADC timing signals are derived
from an on-chip temperature-compensated oscillator. The conversion results can be accessed through the device
serial interface.
7.3.2.1 External Analog Inputs
The AMC7834 has 4 analog inputs for external voltage sensing (ADC1 through ADC4). Figure 47 shows the
equivalent circuit for each external analog input pin. The two diodes, D1 and D2, provide electrostatic discharge
(ESD) protection for the individual analog pins. Diode D1 turns on when any of the inputs is greater than AVDD +
0.3 V. Similarly diode D2 turns on when any of the inputs is less than AGND – 0.3 V. The switch is open while
the ADC is in the READY state.
AVDD
D1
S(W)
RS
C(SAMPLE)
ADCx
D2
S(W) is closed during acquisition.
S(W) is open during conversion.
Figure 47. ADC External Inputs Equivalent Circuit
The analog input range for inputs ADC1 through ADC4 is 0 V to Vref and the LSB (least-significant bit) size is
given by Vref / 4096. The analog input conversion values are stored in straight binary format in the ADC-External
Data registers (address 0x24 through 0x27). The input voltage is calculated using Equation 2.
CODE u Vref
VIN
4096
(2)
To achieve specified performance it is recommended to drive each analog input pin with a low impedance
source. In applications where the signal source has high impedance, analog input must be buffered.
7.3.2.2 Internal Bipolar DAC Monitoring Inputs
The AMC7834 has 4 internal inputs used for monitoring the bipolar DAC outputs (ADCINT1 through ADCINT4).
The internal monitoring inputs are particularly useful when the AMC7834 operates in closed-loop mode as the
bipolar DAC outputs are autonomously updated by the closed-loop controllers. Continuous monitoring of the
bipolar DAC outputs helps in detecting closed-loop controller issues.
The input range for the internal monitoring channels is -2 × Vref to Vref and the LSB size is given by 3 × Vref/4096.
The monitored signals are scaled through a resistor divider so that they map to the native input range of the ADC
(0 to 2 × Vref).
The internal monitoring inputs conversion values are stored in straight binary format in the ADC-Internal Data
registers (address 0x20 through 0x23). The monitored bipolar DAC output voltage is calcualted by Equation 3.
§ V u CODE
·
VADCINT Vref 3 ¨ ref
Vref ¸
4096
©
¹
(3)
30
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7.3.2.3 ADC Sequencing
The AMC7834 supports autonomous and direct-mode ADC conversions. The conversion method is selected in
the AMC configuration 0 register (address 0x10). The default conversion method is autonomous conversion. In
both conversion methods, the channel or group of channels to be converted by the ADC must be first configured
in the ADC MUX register (address 0x12). The input channels to the ADC include 4 external inputs, 4 DAC
monitoring internal inputs, 4 current-sense inputs, 2 remote temperature sensor inputs, and the internal
temperature sensor.
The ADC must be in the READY state before a conversion cycle is started. The ADC enters the READY state
once powered-up and at least one input channel is enabled in the ADC MUX register. The ADC READY status
can be determined either through software (ADC-READY bit in the General Status register, 0x1F) or hardware
(DAV/ADC_RDY pin). To use the DAV/ADC_RDY pin as a READY status indicator, the pin must first be enabled
through the DAVPIN-EN bit in register 0x11. Furthermore the ADC_RDY functionality must be selected by setting
the DAVPIN-SEL bit in register 0x11 to '1'.
The conversion cycle is initiated by setting the ADC-TRIG bit to 1 in the DAC and ADC Trigger register (address
0x1C) which issues an ADC trigger signal. If the trigger signal is issued while the ADC is not in the READY state
it is ignored.
Once the conversion cycle starts the ADC leaves the READY state. In direct-mode conversion upon completion
of the first conversion sequence the ADC returns to the READY state and waits for a new trigger signal.
Alternatively, in autonomous conversion upon completion of the first conversion another sequence is
automatically started. Conversion of the selected channels occurs repeatedly until the conversion is stopped by
issuing another trigger signal, at which point the ADC returns to the READY state.
The following ADC registers should only be updated while the ADC is not in a conversion cycle:
• Device configuration register (address 0x02)
• AMC configuration 0 register (address 0x10)
• AMC configuration 1 register (address 0x11)
• ADC MUX register (address 0x12)
• ALARMOUT configuration register (0x1B)
• Threshold registers (0x40 – 0x4D)
• Hysteresis registers (0x50 – 0x56)
After updating any of the configuration registers listed above, either a minimum 2 µs wait time or READY state
must be ensured before issuing an ADC trigger signal.
Since the ADC is used for voltage, current, and temperature sensor conversions, all of which have significantly
different update times, an interleaved conversion sequence is followed. The interleaved sequence ensures the
wait time between measurement updates is minimized. Figure 48 illustrates the ADC conversion sequence with
all input channels enabled and set to their fastest update time (CS-FILTER[2:0] = 000 and RT-SET[2:0] = 000 in
the AMC Configuration register - 0x10).
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200 µs
1 ms
1 ms
1
2
3
4
5
6
7
8
9
10
11
12
13
14
to
47
8 ms
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TEMPERATURE
SLOT
VOLTAGE
SLOT
24 µs
16 µs
CAL
CS[1-4]
CS-FILTER = 000
ADCEXT1
CS[1-4]
CS-FILTER = 000
ADCEXT2
CS[1-4]
CS-FILTER = 000
ADCEXT3
CS[1-4]
CS-FILTER = 000
ADCEXT4
CS[1-4]
CS-FILTER = 000
CAL
CS[1-4]
CS-FILTER = 000
ADCINT1
CS[1-4]
CS-FILTER = 000
ADCINT2
CS[1-4]
CS-FILTER = 000
ADCINT3
CS[1-4]
CS-FILTER = 000
ADCINT4
CS[1-4]
CS-FILTER = 000
CAL
CS[1-4]
CS-FILTER = 000
ADCEXT1
CS[1-4]
CS-FILTER = 000
ADCEXT2
CS[1-4]
CS-FILTER = 000
LT
54
to
87
8 ms
88
89
90
160 µs
.
.
.
.
.
.
.
.
.
.
RT1
RT-SET = 000
48
49
50
51
52
53
CURRENT
SLOT
ADCINT2
CS[1-4]
CS-FILTER = 000
ADCINT3
CS[1-4]
CS-FILTER = 000
ADCINT4
CS[1-4]
CS-FILTER = 000
CAL
CS[1-4]
CS-FILTER = 000
ADCEXT1
CS[1-4]
CS-FILTER = 000
ADCEXT2
CS[1-4]
CS-FILTER = 000
.
.
.
.
.
.
.
.
.
.
RT2
RT-SET = 000
ADCINT2
CS[1-4]
CS-FILTER = 000
ADCINT3
CS[1-4]
CS-FILTER = 000
ADCINT4
CS[1-4]
CS-FILTER = 000
Figure 48. ADC General Interleaved Sequence
Each ADC interleave step takes 200 µs and is segmented intro three sensing slots: temperature, voltage and
current. The temperature slot is 24 µs long and allocates the temperature sensing channel conversions (internal
temperature sensor and two remote temperature sensors) following the order LT → RT1 → RT2 → LT → ... If
one of the temperature channels is not selected for conversion it is skipped. For example, if RT1 is not selected
for conversion, the temperature slot conversion sequence is LT → RT2 → LT → ... Figure 48 illustrates the
conversion sequence for the lowest remote temperature sensor update time, which is configured by setting RTSET[2:0] = 000 in register 0x10. If a longer temperature sensor is selected to improve measurement accuracy a
higher number of interleave steps is allocated for the remote temperature sensors.
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The voltage slot takes 16 µs and allocates the four external inputs and four DAC monitoring internal inputs
conversions. The external inputs, if enabled, are converted first. If none of the channels in a group (external or
internal) are selected, no time is allocated for conversion of that group. However if at least one of the input
channels in a group is enabled, five interleave steps (1 ms) are allocated regardless of the total number of input
channels.
The current slot allocates the four current sensing channel conversions. The current slot is 160 µs long
independent of how many current sense channels are enabled. The current sensors are updated on each
interleave step (200 µs) when the CS-FILTER[2:0] set to 000 in register 0x10. If a longer current sense update
time is selected to improve measurement accuracy a higher number of interleave steps is allocated for the
current sense conversions.
The update time for all monitoring inputs is determined by the interleave sequence followed. Direct-mode
conversions require an additional 40 µs of update time. In order to simplify synchronization, the AMC7834
provides a data-available signal through the DAV/ADC_RDY pin. The DAV/ADC_RDY pin must first be enabled
through the DAVPIN-EN bit in register 0x11. Furthermore the DAV functionality must be selected by clearing the
DAVPIN-SEL bit in register 0x11 to '0'.
In direct-mode conversion the DAV/ADC_RDY pin goes low after the conversion sequence has been completed.
Additionally, in direct-mode conversion the data available flags in the General status register (address 0x1F) can
be used to determine when new data is available for each data-available channel group. In autonomous
conversion the DAV/ADC_RDY pin indicates when new data is available for each data-available channel group
by issuing a 20 µs pulse (active low).
In both conversion methods the data-available function identifies six channel groups:
1. Current sense inputs: CS1 through CS4
2. External analog inputs: ADC1 through ADC4
3. Internal monitoring inputs: ADCINT1 through ADCINT4
4. Internal temperature sensor: LT
5. Remote temperature sensor 1: RT1
6. Remote temperature sensor 2: RT2
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7.3.3 Temperature Sensors
The AMC7834 device includes one on-chip and two remote temperature sensors. The temperature sensors
monitor the three temperature inputs. The on-chip integrated temperature sensor measures the device
temperature and two remote diode-sensor inputs measure two external temperature points. All three
temperature-sensor results are converted by the device ADC and stored in two’s complement format. If any
sensor is not used, it can be disabled in the register configuration. When any of the temperature sensors is
disabled it is not converted by the ADC.
7.3.3.1 Internal Temperature Sensor
The AMC7834 device has an on-chip temperature sensor that measures the device die temperature. The
temperature-sensor results are converted by the device ADC (see the Analog-to-Digital Converter (ADC) section
for more information). If internal temperature sensor conversion is not needed, it can be disabled in the ADC
MUX register (address 0x12). When disabled the temperature sensor output is not converted by the ADC.
The temperature sensor provides 0.25°C resolution over the device operating temperature range. Additionally,
the AMC7834 internal temperature sensor is specified monotonic down to –55°C. The temperature value is
stored in 12-bit two’s complement format in the LT-data register (address 0x2D).
Table 3. Temperature Sensor Data Format
TEMPERATURE (°C)
DIGITAL CODE
–55
1111 0010 0100
–40
1111 0110 0000
–25
1111 1001 1100
–10
1111 1101 1000
–0.25
1111 1111 1111
0
0000 0000 0000
0.25
0000 0000 0001
10
0000 0010 1000
25
0000 0110 0100
50
0000 1100 1000
75
0001 0010 1100
100
0001 1001 0000
105
0001 1010 0100
125
0001 1111 0100
Use Equation 4 and Equation 5 to calculate the positive or negative temperature according to the polarity of the
temperature data MSB (0 = positive, 1 = negative).
Code
Positive Temperature (qC)
(4)
4
4096 Code
Negative Temperature (qC)
(5)
4
34
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7.3.3.2 Remote Temperature Sensors
The AMC7834 device includes two remote junction-temperature sensors. The remote sensing transistors can be
a discrete, small-signal type transistor or a substrate transistor built within the power amplifier. These transistors
are typically low-cost NPN- or PNP-type transistors such as the 2N3904 and 2N3906. Figure 49 shows the
recommended connection for NPN and PNP transistors in diode configuration.
The AMC7834 device also allows PNP transistor configuration as shown in Figure 50. PNP transistor
configuration for both remote temperature sensors is enabled by setting the RMT-GND-COLL bit to 1 in register
0x11.
NOTE
Pins D1– and D2– are internally shorted. Total parasitic capacitance to AGND on these
pins must be less than 800 pF.
AMC7834
AMC7834
D+
2N3904
NPN
D+
2N3906
PNP
D±
D±
D+
2N3906
PNP
D+
2N3906
PNP
D±
Figure 49. NPN and PNP Diode Configuration
D±
Figure 50. PNP Transistor Configuration
Errors in remote temperature sensor readings are typically the consequence of misalignment in the ideality factor
and current excitation used by the AMC7834 versus the manufacturer-specified operating current for a given
transistor. Some manufacturers specify a low-level (ILOW) and high-level (IHIGH) current for the temperaturesensing substrate transistors. The AMC7834 uses an ILOW of 7 µA and IHIGH of 112 µA and is designed to work
with discrete transistors, such as the 2N3904 and SN3906. If an alternative transistor is used, the following
conditions should be met:
1. Base-emitter voltage (VBE) > 0.25 V at 7 µA for the highest sensed temperature
2. Base-emitter voltage (VBE) < 1.20 V at 112 µA for the lowest sensed temperature
3. Base resistance < 100 Ω
4. Tight control of VBE characteristics indicated by small variations in hFE (50 to 150)
The ideality factor (η) is a measured characteristic of a remote temperature sensor diode as compared to an
ideal one. The AMC7834 is trimmed for η = 1.008. If the selected remote sensing transistor's ideality factor is
different, the effective η-factor should be adjusted at the system level.
Remote junction-temperature sensors are usually implemented in a noisy environment. Noise is most often
created by fast digital signals and can corrupt measurements. A bypass capacitor placed differentially across the
inputs of the remote temperature sensors can make the application more robust against unwanted coupled
signals. If filtering is required, its time constant, including any routing resistance, should be limited to 5 µs or less.
The combined series resistance on the remote temperature sensor pins must be less than 1 kΩ.
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The two remote temperature sensor results are converted by the device ADC (see the Analog-to-Digital
Converter (ADC) section for more information). The two remote temperature sensors can be disabled in the ADC
MUX register (address 0x12). When disabled, the remote temperature sensor outputs are not converted by the
ADC. The remote temperature values are stored in 12-bit two’s complement format in the RT-data registers
(address 0x2E and 0x2F) using the same data format as the internal temperature sensor (see Table 3).
The AMC7834 device enables optimization of the remote temperature measurements by increasing the update
time. The remote temperature-sensor update time is selected by the RT-SET[2:0] setting in register 0x10.
Table 4 lists the total update time for the two remote temperature sensors with respect to the RT-SET[2:0]
setting.
Table 4. Two Remote Temperature Sensors Update
Time
RT-SET[2:0]
TOTAL UPDATE TIME (ms)
000
16
001
16
010
18
011
26
100
50
101
98
All others
Not valid
Optimal remote temperature sensor accuracy is achieved with the current-sense inputs disabled. In applications
requiring simultaneous current-sensor and remote temperature sensor conversions it is recommended to
implement external remote temperature conversion averaging to attain best accuracy results.
36
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7.3.4 Current Sensors
The AMC7834 device integrates four unidirectional high-side current-sense amplifiers that amplify a small
differential voltage developed across a current-sense resistor in the presence of high-input common-mode
voltages. The AMC7834 current-sense amplifiers accept input signals with a common-mode voltage range from 4
V to 60 V. Each amplifier can operate with differential voltages up to 200 mV.
As shown in Figure 51, current flowing through RSENSE develops a voltage drop, VSENSE. The voltage across the
sense resistor, VSENSE, is applied to one of the AMC7834 current-sense amplifier inputs. The current sense
inputs should be connected as closely as possible to the shunt resistor to minimize any resistance in series with
the shunt resistance.
ISENSE
4 V to 60 V
To Load
RSENSE
AMC7834
MUX
SENSE±
VSENSE
ADC
12-b
SENSE+
Figure 51. AMC7834 Current-Sense Amplifier
The accuracy of the current measurement depends heavily on the accuracy of the shunt resistor, R(SENSE). The
use of a Kelvin sense resistor is highly recommended (see Figure 52).
Sense Resistor
Current Flow
from Supply
Current Flow
to Load
SENSE+
SENSE±
AMC7834
Figure 52. Kelvin Connection to the Sense Resistor
The sense-resistor value is application dependent and is typically a compromise between small-signal accuracy,
maximum permissible voltage drop, and allowable power dissipation in the current measurement circuit. For best
results, the value of the resistor is calculated from the maximum-expected load current, ILmax, and the maximum
differential voltage supported by the current-sense amplifier (200 mV). High values of R(SENSE) provide better
accuracy at lower currents by minimizing the effects of the current-sense amplifier offset. Low values of R(SENSE)
minimize load voltage loss, but at the expense of low current accuracy. In general, a compromise between low
current accuracy and load circuit losses must be made.
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The maximum differential voltage, VSENSE, supported by the AMC7834 current-sense amplifiers is 200 mV. Use
Equation 6 to calculate the R(SENSE) value.
R(SENSE) = VSENSE / ILmax
(6)
The maximum power dissipation of the sense resistor should not be exceeded. Use Equation 7 to calculate the
maximum sense resistor power dissipation.
PR(SENSE) = VSENSE × ILmax
(7)
The current sensors operate as four standalone current-sense amplifiers when the AMC7834 is set in open-loop
mode (LOOP-EN bit set to 0 in register 0x10). In open-loop mode the current-sense amplifier outputs are
converted by the device ADC and the results are stored in straight binary format in the CS-Data registers
(address 0x29 through 0x2B). Use Equation 8 to calculate the differential voltage, VSENSE.
CODE u 0.2
VSENSE
4096
(8)
Alternatively, with the AMC7834 set in closed-loop mode (LOOP-EN bit set to 1 in register 0x10) the current
sensors operate as part of four independent closed-loop current controllers. In closed-loop operation, four
autonomous closed-loop current controllers are implemented by continuously adjusting the bipolar DAC outputs
in response to the current-sense amplifier outputs (see the Closed-Loop Mode section).
The AMC7834 device enables digital filtering of the current sense measurements to improve their accuracy at the
cost of a longer update time. The current sense digital filter is enabled by the CS-FILTER[2:0] setting in register
0x10 and its corresponding transfer function is given by Equation 9.
1
H z
1 K 1z 1
(9)
Table 5 lists the K value associated with each of the allowable CS-FILTER[2:0] settings as well as the
corresponding update time.
Table 5. Current Sense Digital Filter Configuration
CS-FILTER[2:0]
K
UPDATE TIME
(ms)
000
1
0.2
001
2
3.4
010
4
6.6
011
8
13
100
16
All others
38
25.6
Not valid
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7.3.5 Drain Switch Control
The AMC7834 device includes an output-control voltage (PA_ON pin) capable of driving an external PMOS
switch that turns on and off the drain current to a PA FET. The use of this control signal in conjunction with the
DAC clamp option allows control of the sequence in which the PA FET is powered up and powered down.
The OFF and ON states of the PA_ON signal are equal to the PAVDD and AGND pins, respectively. The default
state of the PA_ON signal is off (PMOS switch off).
V(DRAIN)
PMOS Switch
PA_ON
PAVDD
PA_ON
Control
RF Out
V(BIAS)
DAC
PA Controller
HPA
RF In
Figure 53. PA_ON Operation
The maximum output voltage is determined by the PAVDD pin and limited to a maximum of 20 V. For PA FETs
with drain voltages higher than 20 V, tying the PAVDD pin to one of the other supply devices (preferably AVDD)
and scaling the control signal externally is recommended.
The PA_ON signal state can be set through a register write, but it can also be configured to be triggered
automatically by the ALARMOUT pin, any of the SLEEP signals or by the special AVSS and AVDD monitoring
circuits.
For FETs requiring a negative bias voltage, such as GaN, ensuring that the bias voltage remains within an
acceptable range is crucial otherwise significant and irreversible damage to the FET can occur. The AMC7834
bipolar DAC operation and clamping mechanism rely on the AVDD and AVSS voltages for proper operation. For
this reason, when either the AVDD or AVSS voltage falls outside its acceptable range, turning off the drain current
to the FET is desirable.
The AVDD detection circuit is set to trigger the PA_ON signal to the OFF state in response to an out of range
event. Additionally, the AVSS detection alarm can be set to trigger the PA_ON signal to the OFF state by setting
the PAON_AVSS bit to 1 in the AMC configuration 1 register (address 0x11). The AVSS alarm is set by default to
prevent the PA_ON output from entering the ON state (PMOS switch on). In this case writing to the PA_ON
register bit to enable the ON state is ignored. If this additional protection is not needed it can be disabled by
clearing the PAON_AVSS bit.
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7.3.6 Programmable Out-of-Range Alarms
The AMC7834 device is capable of continuously analyzing the four internal ADC monitoring inputs (bipolar DACoutput monitoring), current sensors, temperature sensors, and negative supply for normal operation.
Normal operation is established through the lower and upper threshold registers (address 0x40 through 0x4D).
When any of the monitored inputs is out of the specified range, an alarm event is issued and the global alarm bit,
GALARM in the General Status register (address 0x1F), is set (see Figure 54). The alarm status register
(address 0x1E) indicates the source of the alarm event.
DAC4 High Alarm
15
DAC3 High Alarm
14
DAC2 High Alarm
13
DAC1 High Alarm
12
RESERVED
11
AVSS Alarm
10
RT2 High Alarm
9
RT2 Low Alarm
8
ALARM STATUS
0x1E
RT1 High Alarm
7
RT1 Low Alarm
6
LT High Alarm
5
LT Low Alarm
4
ADCINT4/CS4 Alarm
3
ADCINT3/CS3 Alarm
2
ADCINT2/CS2 Alarm
1
ADCINT1/CS1 Alarm
0
GALARM
Figure 54. AMC7834 Alarm Status Register
The ALARM-LATCH-DIS bit in the ALARMOUT configuration register (address 0x1B) sets the latching behavior
for all alarms. When the ALARM-LATCH-DIS bit is cleared to 0 the alarm bits in the alarm status register are
latched. The alarm bits are referred to as being latched because the bits remain set until read by software. This
design ensures that out-of-limit events cannot be missed if the software is periodically polling the device. All bits
are cleared when reading the alarm status register, and all bits are reasserted if the out-of limit condition still
exists on the next monitoring cycle, unless otherwise noted. When the ALARM-LATCH-DIS bit is set to 1, the
alarm bits are not latched. The alarm bits in the alarm status register are set to 0 when the error condition
subsides, regardless of whether the bit is read or not.
All of the alarms can be set to activate the ALARMOUT pin. The ALARMOUT pin is an open-drain pin and
therefore an external pullup resistor to a voltage no higher than that of the AVDD pin is required. The ALARMOUT
output polarity is defined through the ALARMOUT-POLARITY bit in the ALARMOUT configuration register
(address 0x1B). The default polarity is active low (ALARMOUT-POLARITY = 0). The polarity can be changed to
active high by setting the ALARMOUT-POLARITY bit to 1. The ALARMOUT pin works as an interrupt to the host
so that it can query the alarm status register to determine the alarm source. Any alarm event can activate the pin
as long as the alarm is not masked in the ALARMOUT configuration register. When an alarm event is masked,
the occurrence of the event sets the corresponding status bit in the alarm status register, but does not activate
the ALARMOUT pin.
40
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The ALARMOUT status can be configured to automatically clamp specific DACs or set the PA_ON signal to the
OFF state. The ALARMOUT clamp register selects the DAC or DAC pairs that enter the clamp mode as well as
the PA_ON behavior when the ALARMOUT pin is active. Clearing the alarm events does not automatically bring
the DAC or DAC pairs back to normal operation or return the PA_ON to the ON state.
7.3.6.1 ADC Internal Monitoring Input Out-of-Range Alarm
The AMC7834 device can provide out-of-range detection for the four internal ADC inputs monitoring the bipolar
DAC outputs when operating in closed-loop mode. The ADCINT/CS-SELECT bit in register 0x1B must be
cleared to 0 to enable out-of-range detection on the internal ADC inputs.
Figure 55 shows the out-of-range detection block. When the measurement is out-of-range, the corresponding
alarm bit in the alarm status register is set to 1 to flag the out-of-range condition. The values in the
ADCINTn/CSn upper and lower threshold registers (address 0x40 through 0x47) define the upper- and lowerbound thresholds for these inputs when the ADCINT/CS-SELECT bit in the ALARMOUT configuration register
(address 0x1B) is cleared to 0.
ADCINTn-UpperThreshold Value
(upper bound)
±
+
DACn Monitoring
Input
(n = 1 to 4)
ADCINTnALARM
±
ADCINTn-LowerThreshold Value
(lower bound)
+
Figure 55. ADC Monitoring Out-of-Range Alarm
7.3.6.2 Current-Sense Out-of-Range Alarm
The AMC7834 device is capable of providing out-of-range detection for the four current-sense inputs when
operating in open-loop mode. The current-sense out-of-range detection is only active if the ADCINT/CS-SELECT
bit in register 0x1B is set to 1.
Figure 56 shows the current sense detection block. When the measurement is out-of-range, the corresponding
alarm bit in the alarm status register is set to 1 to flag the out-of-range condition. The values in the
ADCINTx/CSx upper and lower threshold registers (address 0x40 through 0x47) define the upper- and lowerbound thresholds for these inputs when the ADCINT/CS-SELECT bit in the ALARMOUT configuration register
(address 0x1B) is set to 1.
CSn-Upper-Threshold
Value
(upper bound)
±
+
Current Sense
Input CSn
(n = 1 to 4)
ADCINTnALARM
±
CSn-Lower-Threshold
Value
(lower bound)
+
Figure 56. Current-Sense Out-of-Range Alarm
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7.3.6.3 Temperature Sensors Out-of-Range Alarm
The AMC7834 device also includes high-limit or low-limit detection for the temperature sensors. Figure 57 shows
the temperature detection block. The values in the temperature sensors upper and lower threshold registers
(address 0x48 through 0x4D) set the limits for the temperature sensors. The temperature sensors can issue
either a high alarm (HIGH-ALARM bit) or a low alarm (LOW-ALARM bit) in the alarm status register (address
0x1E) depending on whether the high or low thresholds were exceeded. To implement single, upper-bound
threshold detection for the temperature sensors, the host processor can set the upper-bound threshold to the
desired value and the lower-bound threshold to the default value. For lower-bound threshold detection, the host
processor can set the lower-bound threshold to the desired value and the upper-bound threshold to the default
value.
(RT1, RT2, LT)
High Threshold
(upper bound)
±
HIGH-ALARM Bit
+
Temperature
Data
(RT1, RT2, LT)
±
(RT1, RT2, LT)
Low Threshold
(lower bound)
LOW-ALARM Bit
+
Figure 57. Temperature Out-of-Range Alarm
7.3.6.4 Bipolar DACs High Alarm
The AMC7834 device includes configurable upper-limit detection for the bipolar DACs in closed-loop mode.
Figure 58 shows the alarm detection block. The values in the bipolar DAC upper threshold registers (address
0x4E through 0x4F) set a limit other than full-scale limit for the bipolar DACs. When a closed-loop controller
attempts to set its bipolar DAC to a value exceeding the corresponding upper-threshold register, the DAC is
instead updated with the threshold value and a DAC high-alarm is issued in the alarm status register.
DACn Upper Threshold
(n = 1 to 4)
±
DACn-HIGH-ALARM
DACn Data Register
(n = 1 to 4)
+
Figure 58. Bipolar DAC High Alarm
7.3.6.5 AVSS Detection Alarm
The device continuously monitors the AVSS supply to ensure it is within the required operating threshold. By
setting the PAON_AVSS bit to 1 in the AMC configuration 1 register (address 0x11) the AVSS alarm can be set to
automatically set the PA_ON pin to the OFF state and prevent it from getting configured back to the ON state
unless the AVSS alarm has been cleared.
7.3.6.6 AVDD Detection Alarm
The device continuously monitors the AVDD supply to ensure it is within the required operating threshold. An
AVDD alarm initiates a POR event which sets the PA_ON pin to the OFF state, bipolar DACs to the AVSS clamp
mode and auxiliary DACs to clamp mode.
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7.3.6.7 Hysteresis
If a monitored signal is out of range and the alarm is enabled, the corresponding alarm bit is set to 1. However,
the alarm condition is cleared only when the conversion result returns either a value lower than the high
threshold register setting or higher than the low threshold register setting by the number of codes specified in the
hysteresis setting (Figure 59). The hysteresis registers (address 0x50 through 0x56) store the hysteresis value
for the programmable alarms. The hysteresis is a programmable value between 0 LSB to 127 LSB for the
internal ADC monitoring and current-sense alarms and 0°C to 31°C for the temperature-sensor alarms.
High Threshold
Hysteresis
Hysteresis
Low Threshold
Over High Alarm
Below Low Alarm
Figure 59. Device Hysteresis
7.3.6.8 False-Alarm Protection
To prevent false alarms, an alarm event is only registered when the monitored signal is out of range for an N
number of consecutive conversions. If the monitored signal returns to the normal range before N consecutive
conversions, an alarm event is not issued. The false alarm factor, N, can be configured in the AMC configuration
1 register (address 0x11).
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7.3.7 Reference Specifications
The AMC7834 device includes a high-performance 2.5 V reference. Operation from an external reference is also
supported.
7.3.7.1 Internal Reference Operation
The AMC7834 device includes a 2.5 V bipolar transistor-based, precision bandgap reference. The internal
reference is externally available at the REF_OUT pin and can be used to drive the ADC and eight DACs by
connecting the REF_OUT pin to the REF_IN pin (see Figure 60). A 10-nF capacitor is recommended between
REF_OUT and AGND for noise filtering. An external buffer amplifier with a high-impedance input must be used to
drive any external load. A compensation capacitor (4.7 μF, typical) should be connected between the REF_CMP
pin and the AGND4 pin.
Internal
Reference
(2.5 V)
REF_OUT
10 nF
(Minimize
inductance to pin)
REF_IN
C > 4.7 µF
(Minimize
inductance to pin)
REF_CMP
DAC Reference
DAC1
12-b
ADC1
MUX
ADC2
ADC
12-b
DAC2
12-b
ADC4
AUXDAC4
12-b
Figure 60. Internal Reference Operation
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7.3.7.2 External Reference Operation
The AMC7834 device can also operate from an external reference. The external reference can be applied to the
REF_IN pin and is used to drive both the ADC and the eight DACs through separate buffers (see Figure 61). As
with the internal-reference case a compensation capacitor (4.7 μF, typical) should be connected between the
REF_CMP pin and the AGND4 pin. The REF_OUT pin can be left floating if unused.
REF_OUT
Internal
Reference
(2.5 V)
REF_IN
C > 4.7 µF
(Minimize
inductance to pin)
External
Reference
(2.5 V)
REF_CMP
DAC Reference
DAC1
12-b
ADC1
MUX
ADC2
ADC
12-b
DAC2
12-b
ADC4
AUXDAC4
12-b
Figure 61. External Reference Operation
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7.3.8 General Purpose I/Os
The AMC7834 device includes four GPIO pins. The GPIO pins can receive an input or produce an output (see
Figure Figure 62). When the GPIOn pin acts as an output, it has an open-drain, and the status of this pin is
determined by the corresponding GPIO bit in the GPIO register (address 0x58). The output state is high
impedance when the GPIOn bit is set to 1, and is logic low when the GPIOn bit is cleared to 0.
NOTE
A 10-kΩ pullup resistor is required when using a GPIO pin as an output. The pullup
voltage must not exceed the AVDD supply.
To use a GPIO pin as an input, the corresponding GPIO bit in the GPIO register must be set to 1. When a GPIO
pin acts as input, the digital value on the pin is acquired by reading the corresponding GPIO bit. After a power-on
reset or any forced reset, all GPIO bits are set to 1, and the GPIO pins enter a high impedance state.
AVDD
GPIOn
ENABLE
GPIOn Bit
(when writing)
GPIOn Bit
(when reading)
Figure 62. AMC7834 GPIO Pin
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7.4 Device Functional Modes
The AMC7834 four high-side current-sense amplifiers and bipolar DACs operate in one of the following modes
as selected by the LOOP-EN bit in register 0x10:
• Open-Loop Mode
• Closed-Loop Mode
7.4.1 Open-Loop Mode
The AMC7834 is set by default in open-loop mode. In open-loop mode, the current-sense amplifiers and bipolar
DACs operate independently.
The AMC7834 four current sensors can operate with differential voltages up to 200 mV and accept commonmode voltages from 4 V to 60 V. The current-sense amplifier outputs are converted by the device ADC and the
results are stored in straight binary format in the CS-Data registers (address 0x29 through 0x2B) to be accessed
by a digital control device for further processing.
The AMC7834 four bipolar DACs are configured as DAC pairs (DAC1-DAC2 and DAC3-DAC4). The output
range for each bipolar DAC pair can be configured through the DAC Range register to one of the following: 0 to 5
V, -5 to 0V, or -4 to 1 V. The POR and clamp value for each DAC pair is set by the pins VCLAMP1 (for the
DAC1-DAC2 pair) and VCLAMP2 (for the DAC3-DAC4 pair) to any voltage between AVSS and 0 V. The full-scale
output range of the bipolar DACs is limited by the power supplies, AVDD and AVSS. In open-loop mode the DAC
output voltage is set by by a digital controller by writing the corresponding code in straight binary format to the
DAC data registers (address 0x30 through 0x33).
Table 6 lists the typical register configurations for open-loop mode.
Table 6. Open-Loop Mode Register Configuration
REGISTER SETTING
REGISTER ADDRESS
COMMENT
LOOP-EN
0x10
Set to 0
CS-FILTER[2:0]
0x10
Configurable
ADCINTn
0x12
Set to 0
LOOPn-SET[3:0]
0x14
Unused
DACn-SYNC
0x15
Configurable
ADCINT/CS-SELECT
0x1B
Set to 1
DACnnLOOP-ALARMEN
0x1B
Set to 0
DACn-HIGH-ALARM
0x1E
Unused
ADCINTn-DATA[11:0]
0x20 to 0x23
Unused
CSn-DATA[11:0]
0x28 to 0x2B
Readable
DACn-DATA[11:0]
0x30 to 0x33
Configurable
CLOSEDLOOPn[11:0]
0x38 to 0x3B
Unused
DACnn-UP-THRES[11:0]
0x4E to 0x4F
Unused
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7.4.2 Closed-Loop Mode
In closed-loop mode the current sensors and bipolar DACs operate as four independent closed-loop current
controllers. In closed-loop operation, four autonomous closed-loop current controllers are implemented by
continuously adjusting the bipolar DAC outputs in response to the current-sense amplifier outputs.
Table 7 lists the typical register configurations for closed-loop mode.
Table 7. Closed-Loop Mode Register Configuration
REGISTER SETTING
REGISTER ADDRESS
COMMENT
LOOP-EN
0x10
Set to 1
CS-FILTER[2:0]
0x10
Configurable
ADCINTn
0x12
Set to 1
LOOPn-SET[3:0]
0x14
Configurable
DACn-SYNC
0x15
Unused
ADCINT/CS-SELECT
0x1B
Set to 0
DACnnLOOP-ALARMEN
0x1B
Configurable
DACn-HIGH-ALARM
0x1E
Used
ADCINTn-DATA[11:0]
0x20 to 0x23
Readable
CSn-DATA[11:0]
0x28 to 0x2B
Unused
DACn-DATA[11:0]
0x30 to 0x33
Unused
CLOSEDLOOPn[11:0]
0x38 to 0x3B
Configurable
DACnn-UP-THRES[11:0]
0x4E to 0x4F
Configurable
Figure 63 shows a typical analog implementation of a closed-loop current controller.
V(DRAIN)
Current Sense
Amplifier
R(SENSE)
DAC
+
PA FET
Gate Drive
Amplifier
Figure 63. Analog Closed-Loop Current Controller
Although the analog current controller is capable of setting and maintaining a given drain current (and therefore,
gain) through a PA FET it lacks the flexibility to scale easily to a large variety of FETs. The AMC7834
implements four closed-loop current controllers as a digital system thus giving it higher flexibility while satisfying
or improving on the specifications given by a typical analog closed-loop current controller.
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VDRAIN
Current-Sense
Amplifier
Serial Interface
Closed Loop Register
SENSE+
Closed Loop Settling
Time Register
ADC
R(SENSE)
I(DRAIN)
SENSE-
RC
Filter
Closed Loop
Register
Slew-Rate
Control
+
Integrator
Bipolar DAC
PA FET
Figure 64. AMC7834 Closed-Loop Current Controller
Each of the four digital control loops consists of a digital integrator and a bipolar DAC in the forward path to drive
the gate of a PA FET. A high-side current-sense amplifier in the feedback path senses the drain bias current and
its output is converted by the device ADC.
As with the DACs in open-loop operation, the closed-loop current controllers can be set to clamp mode. When a
current-controller goes into clamp mode the bipolar DAC output is immediately set to its corresponding clamp
voltage and current-sense conversions are stopped. Note that with the exception of the current-sense inputs all
other monitoring inputs continue to be converted by the device ADC while in clamp mode. Clamping does not
clear the closed-loop state making it possible to return to the same voltage being output before the clamp event
was issued.
Since the drain current does not immediately update in response to the out-of-clamp gate voltage, it is
recommended to stop the ADC conversion prior to leaving the clamp state and re-starting conversion only after
the drain current has stabilized. The stabilization time is dependent on the filtering at the bipolar DAC output and
the PA FET characteristics.
The target drain current is set by the Closed Loop registers (address 0x38 to 0x3B) and is given by Equation 10.
CLOSEDLOOPn >11: 0 @ u Vref
I(DRAIN)
R SENSE u 51200
where
•
•
•
•
I(DRAIN) is the PA drain current (in Amperes)
CLOSEDLOOPn[11:0] is the 12-bit digital code that is input to the control loop to set I(DRAIN)
Vref is the device reference voltage
R(SENSE) is the sense resistor resistance (in Ohms)
(10)
The control loop sets the target drain current by continuously maintaining a constant voltage across the shunt
resistor (V(SENSE) = I(DRAIN) × R(SENSE)). The control loop continuously attempts to zero-out the error at the input of
the integrator by adjusting the DAC output voltage and consequently keeping the drain current constant.
Assuming negligible drift in the sense resistor, any variation in the drain current due to changes in the PA FET
characteristics over time and temperature are automatically tracked and corrected.
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Based on the target drain current and required PA gain ramp rate, the Closed Loop input code step can be
divided by the slew-rate control block into smaller steps that are applied to the control loop every 200 μs. The
slew-rate for each control loop is set by the Closed Loop Settling Time register (address 0x14). Issuing multiple,
smaller code steps over time instead of one large code step helps achieve a more linear PA-gain ramp rate.
Table 8 shows the control-loop settling time as a function of the slew-rate control setting.
Table 8. Closed-Loop Settling Time
LOOPn-SET[3:0]
SETTLING TIME (ms)
0000
0.8
0001
1.6
0010
2.4
0011
3.2
0100
4.8
0101
6.4
0110
9.6
0111
12.8
1000
19.2
1001
25.6
1010
28.8
All others
Not valid
Under normal conditions the code output by the slew-rate control block equals the ADC output in steady state.
When the loop is disturbed as a result of a change on the target drain current or PA characteristics, the error
between the slew-rate controller and ADC outputs is accumulated every 200 μs by the digital integrator. An
optional external RC filter at the DAC output helps to smooth out the DAC steps at the input of the PA FET gate.
The external filter time constant must be less than 50 µs.
The gain from the DAC output to the ADC input is given by Equation 11.
gm(PA_FET) × R(SENSE)
where
•
gm(PA_FET) is the transconductance for the PA FET
(11)
This value should be less than 0.8 to ensure stability of the control loop.
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7.5 Programming
The AMC7834 device is controlled through a flexible four-wire serial interface that is compatible with SPI-type
interfaces used on many microcontrollers and DSP controllers. The interface provides read and write (R/W)
access to all registers of the AMC7834 device.
Each serial-interface access cycle is exactly 24 bits long. A frame is initiated by asserting the CS pin low. The
frame ends when the CS pin is deasserted high. The first bit transferred is the R/W bit. The next 7 bits are the
register address (128 addressable registers), and the remaining 16 bits are data. For all writes, data is clocked in
on the rising edge of SCLK. If the write access is not equal to 24 clocks, the data bits are not committed. On a
read access, data is clocked out on the falling edge of the serial interface clock, SCLK, on the SDO pin.
Figure 65 and Figure 66 show the access protocol used by the interface. Data is accepted as MSB first.
CS
1
2
3
4
5
6
7
R/W
A6
A5
A4
A3
A2
A1
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
SCLK
SDI
A0 D15 D14 D13 D12 D11 D10
SDO
Figure 65. Serial Interface Write Bus Cycle
CS
1
2
3
4
5
6
7
8
R/W
A6
A5
A4
A3
A2
A1
A0
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
SCLK
SDI
SDO
D15 D14 D13 D12 D11 D10
Figure 66. Serial Interface Read Bus Cycle
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7.6 Register Maps
Table 9. Memory Map
ADDRESS
TYPE
DEFAULT
REGISTER NAME
ADDRESS
TYPE
DEFAULT
REGISTER NAME
0x00 to 0x01
—
—
Reserved
0x30
R/W
0000
DAC1-Data
0x02
R/W
0000
Power Mode
0x31
R/W
0000
DAC2-Data
0x03
—
—
Reserved
0x32
R/W
0000
DAC3-Data
0x04
R
0C34
Device ID
0x33
R/W
0000
DAC4-Data
0x05
—
—
Reserved
0x34
R/W
0000
AUXDAC1-Data
0x06
R
0001
Version ID
0x35
R/W
0000
AUXDAC2-Data
0x07 to 0x0B
—
—
Reserved
0x36
R/W
0000
AUXDAC3-Data
0x0C
R
0451
Vendor ID
0x37
R/W
0000
AUXDAC4-Data
0x0D – 0x0F
—
—
Reserved
0x38
R/W
0000
ClosedLoop1
0x10
R/W
0300
AMC Configuration 0
0x39
R/W
0000
ClosedLoop2
0x11
R/W
036A
AMC Configuration 1
0x3A
R/W
0000
ClosedLoop3
0x12
R/W
0000
ADC MUX
0x3B
R/W
0000
ClosedLoop4
0x13
—
—
Reserved
0x3C to 0x3F
—
—
Reserved
0x14
R/W
2222
Closed Loop Settling Time
0x40
R/W
0FFF
ADCINT1/CS1-Upper-Thresh
0x15
R/W
0000
DAC Sync
0x41
R/W
0000
ADCINT1/CS1-Lower-Thresh
0x16
R/W
0000
DAC Range
0x42
R/W
0FFF
ADCINT2/CS2-Upper-Thresh
0x17
R/W
003F
CLAMP Configuration
0x43
R/W
0000
ADCINT2/CS2-Lower-Thresh
0x18
R/W
FF00
SLEEP1 Configuration
0x44
R/W
0FFF
ADCINT3/CS3-Upper-Thresh
0x19
R/W
FF00
SLEEP2 Configuration
0x45
R/W
0000
ADCINT3/CS3-Lower-Thresh
0x1A
R/W
0000
ALARMOUT Clamp
0x46
R/W
0FFF
ADCINT4/CS4-Upper-Thresh
0x1B
R/W
0000
ALARMOUT Configuration
0x47
R/W
0000
ADCINT4/CS4-Lower-Thresh
0x1C
W
0000
DAC/ADC Trigger
0x48
R/W
07FF
LT-Upper-Thresh
0x1D
W
0000
Software Reset
0x49
R/W
0800
LT-Lower-Thresh
0x1E
R
0000
Alarm Status
0x4A
R/W
07FF
RT1-Upper-Thresh
0x1F
R
0000
AMC Status
0x4B
R/W
0800
RT1-Lower-Thresh
0x20
R
0000
ADC1-Internal-Data
0x4C
R/W
07FF
RT2-Upper-Thresh
0x21
R
0000
ADC2-Internal-Data
0x4D
R/W
0800
RT2-Lower-Thresh
0x22
R
0000
ADC3-Internal-Data
0x4E
R/W
0FFF
DAC12-Upper-Thresh
0x23
R
0000
ADC4-Internal-Data
0x4F
R/W
0FFF
DAC34-Upper-Thresh
0x24
R
0000
ADC1-External-Data
0x50
R/W
0008
ADCINT1/CS1-Hysteresis
0x25
R
0000
ADC2-External-Data
0x51
R/W
0008
ADCINT2/CS2-Hysteresis
0x26
R
0000
ADC3-External-Data
0x52
R/W
0008
ADCINT3/CS3-Hysteresis
0x27
R
0000
ADC4-External-Data
0x53
R/W
0008
ADCINT4/CS4-Hysteresis
0x28
R
0000
CS1-Data
0x54
R/W
0008
LT-Hysteresis
0x29
R
0000
CS2-Data
0x55
R/W
0008
RT1-Hysteresis
0x2A
R
0000
CS3-Data
0x56
R/W
0008
RT2-Hysteresis
Reserved
52
0x2B
R
0000
CS4-Data
0x57
—
—
0x2C
—
—
Reserved
0x58
R/W
000F
GPIO
0x2D
R
0000
LT-Data
0x59 to 0x5F
—
—
Reserved
0x2E
R
0000
RT1-Data
0x60 to 0x6F
—
—
Reserved
0x2F
R
0000
RT2-Data
0x70 to 0x7F
—
—
Reserved
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Register Maps (continued)
7.6.1 Power Mode: Address 0x02
7.6.1.1 Power Mode Register (address = 0x02) [reset = 0x000]
Figure 67. Power Mode Register (R/W)
15
14
13
12
11
10
9
3
2
1
8
Reserved
R/W-00h
7
6
5
4
Reserved
R/W-00h
0
POWER-MODE
R/W-00
Table 10. Power Mode Register Field Descriptions
Field
Type
Reset
Description
15-2
Bit
Reserved
R/W
All zeros
Reserved for factory use.
1–0
POWER-MODE
R/W
00
Power down mode for the AMC7834 device.
See Table 11.
Table 11. POWER-MODE Configuration
POWER
MODE
Value
Reference
Current
Sensors
ADC
ADC
Reference
Buffer
DAC
Reference
Buffer
Auxiliary
DACs
Bipolar
DACs
Power-Down
Mode
0x
ON
OFF
OFF
OFF
OFF
OFF
ON
Active Mode
10
ON
ON
ON
ON
ON
ON
ON
Reserved
Mode
11
Not valid. Reserved for factory use.
7.6.2 Device Identification: Address 0x04 through 0x0C
7.6.2.1 Device ID Register (address = 0x04) [reset = 0x0C34]
Figure 68. Device ID Register (R)
15
14
13
12
11
10
9
8
3
2
1
0
DEVICEID
R-0Ch
7
6
5
4
DEVICEID
R-34h
Table 12. Device ID Register Field Descriptions
Bit
15-0
Field
Type
Reset
Description
DEVICEID
R
0C34h
Device ID.
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7.6.2.2 Version ID Register (address = 0x06) [reset = 0x0001]
Figure 69. Version ID Register (R)
15
14
13
12
11
10
9
8
3
2
1
0
VERSIONID
R-00h
7
6
5
4
VERSIONID
R-01h
Table 13. Version ID Register Field Descriptions
Bit
15-0
Field
Type
Reset
Description
VERSIONID
R
0001h
AMC7834 version ID. Subject to change.
7.6.2.3 Vendor ID Register (address = 0x0C) [reset = 0x0451]
Figure 70. Vendor ID Register (R)
15
14
13
12
11
10
9
8
3
2
1
0
VENDORID
R-04h
7
6
5
4
VENDORID
R-51h
Table 14. Vendor ID Register Field Descriptions
Bit
15-0
54
Field
Type
Reset
Description
VENDORID
R
0451h
Vendor ID.
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7.6.3 General Device Configuration: Address 0x10 through 0x16
7.6.3.1 AMC Configuration 0 Register (address = 0x10) [reset = 0x0300]
Figure 71. AMC Configuration 0 Register (R/W)
15
14
Reserved
R/W-000
13
12
CMODE
R/W-0
11
Reserved
R/W-0
10
9
CS-FILTER[2:0]
R/W-011
8
7
Reserved
R/W-0
6
5
RT-SET[2:0]
R/W-000
4
3
2
Reserved
R/W-000
1
0
LOOP-EN
R/W-0
Table 15. AMC Configuration 0 Field Descriptions
Field
Type
Reset
Description
15-13
Bit
Reserved
R/W
000
Reserved for factory use.
12
CMODE
R/W
0
0: Autonomous ADC conversion
1: Direct-mode ADC conversion
11
Reserved
R/W
0
Reserved for factory use.
CS-FILTER[2:0]
R/W
011
Current sense filter setting. Improves noise of current sensors
measurements by trading off the update time. The digital filter
has the transfer function:
10-8
1
H z
1
K 1z
1
(12)
See Table 16 for its configuration.
7
Reserved
R/W
0
Reserved for factory use.
6-4
RT-SET[2:0]
R/W
000
Improves noise of the remote temperature sensors
measurements by trading off the update time. See Table 17 for
its configuration.
3-1
Reserved
R/W
000
Reserved for factory use.
0
LOOP-EN
R/W
0
When set to 1 enables closed-loop mode operation.
Table 16. CS-FILTER Configuration
CS-FILTER[2:0]
K
Approximate Update Time (ms)
000
1
0.2
001
2
3.4
010
4
6.6
011
8 (default)
13
100
16
25.6
All others
Not valid
Table 17. RT-SET Configuration
RT-SET[2:0]
Two Remote Sensors Update Time (ms)
000
16
001
16
010
18
011
26
100
50
101
98
All others
Not valid
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7.6.3.2 AMC Configuration 1 Register (address = 0x11) [reset = 0x036A]
Figure 72. AMC Configuration 1 Register (R/W)
15
DAVPIN-EN
R/W-0
14
DAVPIN-SEL
R/W-0
13
7
RMT-GNDCOLL
R/W-0
6
PAON_AVSS
5
R/W-1
12
Reserved
R/W-000
11
4
3
10
9
CH-FALR[2:0]
R/W-011
8
2
1
0
LT-FALR[1:0]
RT2-FALR[1:0]
RT1-FALR[1:0]
R/W-10
R/W-10
R/W-10
Table 18. AMC Config1 Field Descriptions
Bit
Field
Type
Reset
Description
15
DAVPIN-EN
R/W
0
When set to 1 it enables the DAV/ADC_RDY pin output function.
When cleared to 0 the DAV/ADC_RDY pin is in high impedance
mode.
14
DAVPIN-SEL
R/W
0
When cleared to 0 and if DAVPIN-EN is equal to 1 the
DAV/ADC_RDY pin operates as a DAV pin.
When set to 1 and if DAVPIN-EN is equal to 1 the
DAV/ADC_RDY pin operates as an ADC_RDY pin.
13-11
10
Reserved
R/W
000
Reserved for factory use.
CH-FALR[2:0]
R/W
011
False alarm protection for ADC channels. Use the following
configurations for the consecutive samples before the alarm is
set:
000: 1
001: 4
010: 8
011: 16 (default)
100: 32
101: 64
110: 128
111: 256
7
RMT-GND-COLL
R/W
0
When set to 1 enables PNP transistor configuration on both
remote temperature sensors.
6
PAON_AVSS
R/W
1
When PAON_AVSS = 1 an AVSS alarm event automatically
switches the PA_ON pin to the OFF state.
The AVSS alarm must be cleared before the PA_ON pin can be
switch back to the ON state.
When PAON_AVSS = 0 the PA_ON pin is unaffected by an
AVSS alarm event.
5-4
LT-FALR[1:0]
R/W
10
False alarm protection for local temperature sensor. Use the
following configurations for the consecutive samples before the
alarm is set:
00: 1
01: 2
10: 4 (default)
11: 8
56
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Table 18. AMC Config1 Field Descriptions (continued)
Bit
Field
Type
Reset
Description
3-2
RT2-FALR[1:0]
R/W
10
False alarm protection for remote temperature sensor 2 (D2+,
D2–). Use the following configurations for the consecutive
samples before the alarm is set:
00: 1
01: 2
10: 4 (default)
11: 8
1–0
RT1-FALR[1:0]
R/W
10
False alarm protection for remote temperature sensor 1 (D1+,
D1–). Use the following configurations for the consecutive
samples before the alarm is set:
00: 1
01: 2
10: 4 (default)
11: 8
7.6.3.3 ADC MUX Register (address = 0x12) [reset = 0x0000]
Figure 73. ADC MUX Register (R/W)
15
Reserved
R/W-0
14
LT
R/W-0
13
RT2
R/W-0
12
RT1
R/W-0
11
CS4
R/W-0
10
CS3
R/W-0
9
CS2
R/W-0
8
CS1
R/W-0
7
ADCEXT4
R/W-0
6
ADCEXT3
R/W-0
5
ADCEXT2
R/W-0
4
ADCEXT1
R/W-0
3
ADCINT4
R/W-0
2
ADCINT3
R/W-0
1
ADCINT2
R/W-0
0
ADCINT1
R/W-0
Table 19. ADC MUX Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R/W
0
14
LT
R/W
0
When set to 1 the corresponding analog input channel to the
ADC mux is accessed during an ADC conversion cycle.
13
RT2
R/W
0
12
RT1
R/W
0
11
CS4
R/W
0
10
CS3
R/W
0
9
CS2
R/W
0
8
CS1
R/W
0
7
ADCEXT4
R/W
0
6
ADCEXT3
R/W
0
5
ADCEXT2
R/W
0
4
ADCEXT1
R/W
0
3
ADCINT4
R/W
0
2
ADCINT3
R/W
0
1
ADCINT2
R/W
0
0
ADCINT1
R/W
0
When cleared to 0 the corresponding input channel to the ADC
mux is ignored during an ADC conversion cycle.
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7.6.3.4 Closed Loop Settling Time Register (address = 0x14) [reset = 0x2222]
Figure 74. Closed Loop Settling Time Register (R/W)
15
14
13
LOOP4-SET[3:0]
R/W-0010
12
11
10
9
LOOP3-SET[3:0]
R/W-0010
8
7
6
5
LOOP2-SET[3:0]
R/W-0010
4
3
2
1
LOOP1-SET[3:0]
R/W-0010
0
Table 20. Closed Loop Settling Time Register Field Descriptions
Field
Type
Reset
Description
15-12
Bit
LOOP4-SET[3:0]
R/W
0010
11–8
LOOP3-SET[3:0]
R/W
0010
7-4
LOOP2-SET[3:0]
R/W
0010
Slew rate controller. Sets the maximum voltage transition rate of
each closed-loop current controller. See Table 21 for its
configuration.
3-0
LOOP1-SET[3:0]
R/W
0010
Table 21. Closed-Loop Settling Time Configuration
58
LOOPn-SET[3:0]
Settling Time (ms)
0000
0.8
0001
1.6
0010
2.4
0011
3.2
0100
4.8
0101
6.4
0110
9.6
0111
12.8
1000
19.2
1001
25.6
1010
28.8
All others
Not valid
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7.6.3.5 DAC Sync Register (address = 0x15) [reset = 0x0000]
Figure 75. DAC Sync Register (R/W)
15
14
13
12
11
10
9
8
3
DAC4-SYNC
2
DAC3-SYNC
1
DAC2-SYNC
0
DAC1-SYNC
R/W-0
R/W-0
R/W-0
R/W-0
Reserved
R/W-00h
7
AUXDAC4SYNC
R/W-0
6
AUXDAC3SYNC
R/W-0
5
AUXDAC2SYNC
R/W-0
4
AUXDAC1SYNC
R/W-0
Table 22. DAC Sync Register Field Descriptions
Bit
Field
Type
Reset
Description
Reserved
R/W
0x00
Reserved for factory use.
7
AUXDAC4-SYNC
R/W
0
6
AUXDAC3-SYNC
R/W
0
When set to 1 the corresponding DAC output is set to
synchronous-mode.
5
AUXDAC2-SYNC
R/W
0
4
AUXDAC1-SYNC
R/W
0
3
DAC4-SYNC
R/W
0
2
DAC3-SYNC
R/W
0
1
DAC2-SYNC
R/W
0
0
DAC1-SYNC
R/W
0
15-8
When cleared to 0 the corresponding DAC output is set to
asynchronous-mode.
In closed-loop mode DAC1, DAC2, DAC3 and DAC4 are always
in asynchronous-mode.
7.6.3.6 DAC Range Register (address = 0x16) [reset = 0x0000]
Figure 76. DAC Range Register (R/W)
15
14
13
12
11
10
9
8
Reserved
R/W-00h
7
AUXDAC4RANGE
R/W-0
6
AUXDAC3RANGE
R/W-0
5
AUXDAC2RANGE
R/W-0
4
AUXDAC1RANGE
R/W-0
3
2
DAC34-RANGE[1:0]
1
0
DAC12-RANGE[1:0]
R/W-00
R/W-00
Table 23. DAC Range Register Field Descriptions
Bit
Field
Type
Reset
Description
Reserved
R/W
0x00
Reserved for factory use.
7
AUXDAC4-RANGE
R/W
0
6
AUXDAC3-RANGE
R/W
0
When cleared to 0 the corresponding AUXDAC output range is 0
to 5 V.
5
AUXDAC2-RANGE
R/W
0
15-8
4
AUXDAC1-RANGE
R/W
0
3-2
DAC34-RANGE[1:0]
R/W
00
1–0
DAC12-RANGE[1:0]
R/W
00
When set to 1 the corresponding AUXDAC output range is 2.5 to
7.5 V.
Sets the bipolar DAC output range. Use the following
configurations for the DAC output range:
00: –4 to 1 V
01: –5 to 0 V
10: –5 to 0 V
11: 0 to 5 V
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7.6.4 Clamp and Alarm Configuration: Address 0x17 through 0x1B
7.6.4.1 CLAMP Configuration Register (address = 0x17) [reset = 0x003F]
Figure 77. CLAMP Configuration Register (R/W)
15
14
13
12
11
10
3
AUXDAC2CLAMP
R/W-1
2
AUXDAC1CLAMP
R/W-1
9
8
Reserved
R/W-00h
7
Reserved
6
PAON
R/W-0
R/W-0
5
AUXDAC4CLAMP
R/W-1
4
AUXDAC3CLAMP
R/W-1
1
0
DAC34-CLAMP DAC12-CLAMP
R/W-1
R/W-1
Table 24. CLAMP Configuration Field Descriptions
Bit
15-7
6
Field
Type
Reset
Description
Reserved
R/W
All zeros
Reserved for factory use.
PAON
R/W
0
Direct control of the PA_ON pin.
When cleared to 0 the PA_ON pin is in the OFF state (PAVDD).
When set to 1 the PA_ON pin is in the ON state (AGND).
When read, the value of this bit reflects the state of the PA_ON
pin.
60
5
AUXDAC4-CLAMP
R/W
1
4
AUXDAC3-CLAMP
R/W
1
3
AUXDAC2-CLAMP
R/W
1
2
AUXDAC1-CLAMP
R/W
1
1
DAC34-CLAMP
R/W
1
0
DAC12-CLAMP
R/W
1
This register uses software to force the corresponding DAC into
clamp.
If 1, the corresponding DAC or DAC pair is forced into
clamp.
If 0, the corresponding DAC or DAC pair is restored to
normal operation.
If a DAC or DAC pair is in clamp mode through a SLEEP pin the
corresponding clamp bit is automatically set to 1.
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7.6.4.2 SLEEP1 Configuration Register (address = 0x18) [reset = 0xFF00]
Figure 78. SLEEP1 Configuration Register (R/W)
15
Reserved
R/W-1
14
PAONSNOOZE1
R/W-1
13
AUXDAC4SNOOZE1
R/W-1
12
AUXDAC3SNOOZE1
R/W-1
11
AUXDAC2SNOOZE1
R/W-1
10
AUXDAC1SNOOZE1
R/W-1
9
DAC34SNOOZE1
R/W-1
8
DAC12SNOOZE1
R/W-1
7
Reserved
6
PAON-SLEEP1
R/W-0
R/W-0
5
AUXDAC4SLEEP1
R/W-0
4
AUXDAC3SLEEP1
R/W-0
3
AUXDAC2SLEEP1
R/W-0
2
AUXDAC1SLEEP1
R/W-0
1
DAC34SLEEP1
R/W-0
0
DAC12SLEEP1
R/W-0
Table 25. SLEEP1 Configuration Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R/W
1
Reserved for factory use.
14
PAON-SNOOZE1
R/W
1
Setting this bit to 1 imposes an additional write to the PA_ON
register to set the PA_ON pin to the ON state after clearing the
SLEEP1 pin.
Setting this bit to 0 enables the SLEEP1 pin to set the PA_ON
pin to the ON state directly.
13
AUXDAC4-SNOOZE1
R/W
1
12
AUXDAC3-SNOOZE1
R/W
1
11
AUXDAC2-SNOOZE1
R/W
1
10
AUXDAC1-SNOOZE1
R/W
1
9
DAC34-SNOOZE1
R/W
1
8
DAC12-SNOOZE1
R/W
1
7
Reserved
R/W
0
Reserved for factory use
6
PAON-SLEEP1
R/W
0
Setting this bit to 1 allows control of the PA_ON pin through the
SLEEP1 pin. When SLEEP1 pin goes high the PA_ON pin
enters the OFF state.
Setting any of these bits to 1 imposes an additional write to the
CLAMP Configuration register to wake-up the corresponding
DAC or DAC pair from clamp after clearing the SLEEP1 pin.
Clearing any of these bits to 0 enables the SLEEP1 pin to wakeup the DAC or DAC pairs directly.
Bringing the SLEEP1 pin low is required but not necessarily
sufficient to return the PA_ON pin to the ON state as determined
by the SNOOZE bits.
Setting this bit to 0 causes the PA_ON pin to be unaffected by
the SLEEP1 pin.
5
AUXDAC4-SLEEP1
R/W
0
4
AUXDAC3-SLEEP1
R/W
0
3
AUXDAC2-SLEEP1
R/W
0
2
AUXDAC1-SLEEP1
R/W
0
1
DAC34-SLEEP1
R/W
0
0
DAC12-SLEEP1
R/W
0
Setting any of these bits to 1 allows control of the corresponding
DAC or DAC pair through the SLEEP1 pin. When SLEEP1 pin
goes high the DAC or DAC pair goes into clamp mode.
Bringing the SLEEP1 pin low is required but not necessarily
sufficient to return the DAC or DAC pairs to normal operation as
determined by the SNOOZE bits.
Clearing any of these bits to 0 causes the corresponding DAC or
DAC pair to be unaffected by the SLEEP1 pin.
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7.6.4.3 SLEEP2 Configuration Register (address = 0x19) [reset = 0xFF00]
Figure 79. SLEEP2 Configuration Register (R/W)
15
Reserved
R/W-1
14
PAONSNOOZE2
R/W-1
13
AUXDAC4SNOOZE2
R/W-1
12
AUXDAC3SNOOZE2
R/W-1
11
AUXDAC2SNOOZE2
R/W-1
10
AUXDAC1SNOOZE2
R/W-1
9
DAC34SNOOZE2
R/W-1
8
DAC12SNOOZE2
R/W-1
7
Reserved
6
PAON-SLEEP2
R/W-0
R/W-0
5
AUXDAC4SLEEP2
R/W-0
4
AUXDAC3SLEEP2
R/W-0
3
AUXDAC2SLEEP2
R/W-0
2
AUXDAC1SLEEP2
R/W-0
1
DAC34SLEEP2
R/W-0
0
DAC12SLEEP2
R/W-0
Table 26. SLEEP2 Configuration Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R/W
1
Reserved for factory use
14
PAON-SNOOZE2
R/W
1
Setting this bit to 1 imposes an additional write to the PA_ON
register to set the PA_ON pin to the ON state after clearing the
SLEEP2 pin.
Setting this bit to 0 enables the SLEEP2 pin to set the PA_ON
pin to the ON state directly.
13
AUXDAC4-SNOOZE2
R/W
1
12
AUXDAC3-SNOOZE2
R/W
1
11
AUXDAC2-SNOOZE2
R/W
1
10
AUXDAC1-SNOOZE2
R/W
1
9
DAC34-SNOOZE2
R/W
1
8
DAC12-SNOOZE2
R/W
1
7
Reserved
R/W
0
Reserved for factory use
6
PAON-SLEEP2
R/W
0
Setting this bit to 1 allows control of the PA_ON pin through the
SLEEP2 pin. When SLEEP2 pin goes high the PA_ON pin
enters the OFF state.
Setting any of these bits to 1 imposes an additional write to the
CLAMP Configuration register to wake-up the corresponding
DAC or DAC pair from clamp after clearing the SLEEP2 pin.
Clearing any of these bits to 0 enables the SLEEP2 pin to wakeup the DAC or DAC pairs directly.
Bringing the SLEEP2 pin low is required but not necessarily
sufficient to return the PA_ON pin to the ON state as determined
by the SNOOZE bits.
Setting this bit to 0 causes the PA_ON pin to be unaffected by
the SLEEP2 pin.
62
5
AUXDAC4-SLEEP2
R/W
0
4
AUXDAC3-SLEEP2
R/W
0
3
AUXDAC2-SLEEP2
R/W
0
2
AUXDAC1-SLEEP2
R/W
0
1
DAC34-SLEEP2
R/W
0
0
DAC12-SLEEP2
R/W
0
Setting any of these bits to 1 allows control of the corresponding
DAC or DAC pair through the SLEEP2 pin. When SLEEP2 pin
goes high the DAC or DAC pair goes into clamp mode.
Bringing the SLEEP2 pin low is required but not necessarily
sufficient to return the DAC or DAC pairs to normal operation as
determined by the SNOOZE bits.
Clearing any of these bits to 0 causes the corresponding DAC or
DAC pair to be unaffected by the SLEEP2 pin.
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7.6.4.4 ALARMOUT Clamp Register (address = 0x1A) [reset = 0x0000]
Figure 80. ALARMOUT Clamp Register (R/W)
15
14
13
12
11
10
9
8
3
AUXDAC2ALARMOUT
R/W-0
2
AUXDAC1ALARMOUT
R/W-0
1
DAC34ALARMOUT
R/W-0
0
DAC12ALARMOUT
R/W-0
Reserved
R/W-00h
7
Reserved
R/W-0
6
PAONALARMOUT
R/W-0
5
AUXDAC4ALARMOUT
R/W-0
4
AUXDAC3ALARMOUT
R/W-0
Table 27. ALARMOUT Clamp Register Field Descriptions
Bit
15-7
6
Field
Type
Reset
Description
Reserved
R/W
All zeros
Reserved for factory use.
PAON-ALARMOUT
R/W
0
PAON-ALARMOUT = 1 allows control of the PA_ON pin through
ALARMOUT. When ALARMOUT is active the PA_ON pin goes
into the OFF state.
Clearing the alarms does not return PA_ON to the ON state.
PAON-ALARMOUT = 0 causes the PA_ON pin to be unaffected
by ALARMOUT.
5
AUXDAC4-ALARMOUT
R/W
0
4
AUXDAC3-ALARMOUT
R/W
0
3
AUXDAC2-ALARMOUT
R/W
0
2
AUXDAC1-ALARMOUT
R/W
0
1
DAC34-ALARMOUT
R/W
0
0
DAC12-ALARMOUT
R/W
0
Setting any of these bits to 1 allows control of the corresponding
DAC or DAC pair clamp through ALARMOUT. When
ALARMOUT is active the DAC or DAC pair goes into clamp
mode.
Clearing the alarms does not return the DAC or DAC pairs to
normal operation.
Clearing any of these bits to 0 causes the corresponding DAC or
DAC pair to be unaffected by ALARMOUT.
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7.6.4.5 ALARMOUT Configuration Register (address = 0x1B) [reset = 0x0000]
Figure 81. ALARMOUT Configuration Register (R/W)
15
ALARMLATCH-DIS
R/W-0
14
ALARMOUTPOLARITY
R/W-0
13
ADCINT/CSSELECT
R/W-0
12
DAC34LOOPALARMEN
R/W-0
11
DAC12LOOPALARMEN
R/W-0
10
AVSSALARMEN
R/W-0
9
RT2-HIGHALARMEN
R/W-0
8
RT2-LOWALARMEN
R/W-0
7
RT1-HIGHALARMEN
R/W-0
6
RT1-LOWALARMEN
R/W-0
5
LT-HIGHALARMEN
R/W-0
4
LT-LOWALARMEN
R/W-0
3
ADCINT4/CS4ALARMEN
R/W-0
2
ADCINT3/CS3ALARMEN
R/W-0
1
ADCINT2/CS2ALARMEN
R/W-0
0
ADCINT1/CS1ALARMEN
R/W-0
Table 28. ALARMOUT Configuration Field Descriptions
Bit
Field
Type
Reset
Description
15
ALARM-LATCH-DIS
R/W
0
Alarm latch disable bit.
When cleared to 0 the alarm bits are latched. When an alarm
occurs, the corresponding alarm bit is set to 1. The alarm bit
remains until the error condition subsides and the alarm register
is read. Before reading, the alarm bit is not cleared even if the
alarm condition disappears.
When set to 1 the alarm bits are not latched. When the alarm
condition subsides, the alarm bits are cleared regardless of
whether the alarm bits have been read or not.
14
ALARMOUT-POLARITY
R/W
0
ALARMOUT polarity bit.
When cleared to 0 the ALARMOUT pin is active low.
When set to 1 the ALARMOUT pin is active high.
13
ADCINT/CS-SELECT
R/W
0
When cleared to 0 the threshold values in registers 0x40 to 0x47
apply to ADC inputs ADCINT[1–4]. This setting should be used
for closed-loop mode operation.
When set to 1 the threshold values in registers 0x40 to 0x47
apply to current sense measurements CS[1–4]. This setting
should be used for open-loop mode operation.
64
12
DAC34LOOP-ALARMEN
R/W
0
11
DAC12LOOP-ALARMEN
R/W
0
10
AVSS-ALARMEN
R/W
0
9
RT2-HIGH-ALARMEN
R/W
0
8
RT2-LOW-ALARMEN
R/W
0
7
RT1-HIGH-ALARMEN
R/W
0
6
RT1-LOW-ALARMEN
R/W
0
5
LT-HIGH-ALARMEN
R/W
0
4
LT-LOW-ALARMEN
R/W
0
3
ADCINT4/CS4-ALARMEN
R/W
0
2
ADCINT3/CS3-ALARMEN
R/W
0
1
ADCINT2/CS2-ALARMEN
R/W
0
0
ADCINT1/CS1-ALARMEN
R/W
0
These bits select the alarm events that trigger the ALARMOUT
pin.
When set to 1 an alarm event associated with the corresponding
bit will trigger the ALARMOUT pin.
When cleared to 0 an alarm event associated with the
corresponding bit does not affect the ALARMOUT pin.
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7.6.5 Conversion Trigger: Address 0x1C
7.6.5.1 DAC and ADC Trigger Register (address = 0x1C) [reset = 0x0000]
Figure 82. DAC and ADC Trigger Register (W)
15
14
13
12
11
10
9
8
3
2
1
DAC-TRIG
W-0
0
ADC-TRIG
W-0
Reserved
W-00h
7
6
5
4
Reserved
W-00h
Table 29. DAC/ADC Trigger Field Descriptions
Field
Type
Reset
Description
15-2
Bit
Reserved
W
All zeros
Reserved for factory use.
1
DAC-TRIG
W
0
Internal DAC conversion trigger.
Set this bit to 1 to synchronously load those DACs who have
been set in synchronous mode in the DAC Sync register. This
bit is automatically cleared to 0 after the DAC Data registers are
updated.
0
ADC-TRIG
W
0
Internal ADC conversion bit.
Set this bit to 1 to start the ADC conversion. The bit is
automatically cleared to 0 after the ADC conversion starts. If the
bit is set to 1 while the ADC is not in READY mode the
conversion command is ignored.
7.6.6 Reset: Address 0x1D
7.6.6.1 Software Reset Register (address = 0x1D) [reset = 0x0000]
Figure 83. Software Reset Register (W)
15
14
13
12
11
10
9
8
3
2
1
SOFT-RESET[3:0]
W-0000
0
Reserved
W-00h
7
6
5
4
Reserved
W-0000
Table 30. Software Reset Register Field Descriptions
Bit
Field
Type
Reset
Description
15-4
Reserved
W
All zeros
Reserved for factory use.
3-0
SOFT-RESET[3:0]
W
0000
When set to reserved code 1100 resets the device to its default
state. Auto clears with execution.
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7.6.7 Device Status: Address 0x1E and 0x1F
7.6.7.1 Alarm Status Register (address = 0x1E) [reset = 0x0000]
Figure 84. Alarm Status Register (R)
15
DAC4-HIGHALARM
R-0
14
DAC3-HIGHALARM
R-0
13
DAC2-HIGHALARM
R-0
12
DAC1-HIGHALARM
R-0
11
Reserved
10
AVSS-ALARM
R-0
9
RT2-HIGHALARM
R-0
8
RT2-LOWALARM
R-0
R-0
7
RT1-HIGHALARM
R-0
6
RT1-LOWALARM
R-0
5
LT-HIGHALARM
R-0
4
LT-LOWALARM
R-0
3
ADCINT4/CS4ALARM
R-0
2
ADCINT3/CS3ALARM
R-0
1
ADCINT2/CS2ALARM
R-0
0
ADCINT1/CS1ALARM
R-0
Table 31. Alarm Status Register Field Descriptions
Bit
Field
Type
Reset
Description
15
DAC4-HIGH-ALARM
R
0
DAC4-HIGH-ALARM = 1 when DAC4 has exceeded the upper
output limit set by DAC34-UP-THRESH[11:0].
14
DAC3-HIGH-ALARM
R
0
DAC3-HIGH-ALARM = 1 when DAC3 has exceeded the upper
output limit set by DAC34-UP-THRESH[11:0].
13
DAC2-HIGH-ALARM
R
0
DAC2-HIGH-ALARM = 1 when DAC2 has exceeded the upper
output limit set by DAC12–UP-THRESH[11:0].
12
DAC1-HIGH-ALARM
R
0
DAC1-HIGH-ALARM = 1 when DAC1 has exceeded the upper
output limit set by DAC12–UP-THRESH[11:0].
11
Reserved
R
0
Reserved for factory use.
10
AVSS-ALARM
R
0
AVSS_ALARM = 1 when AVSS is out of range.
9
RT2-HIGH-ALARM
R
0
RT2-HIGH-ALARM = 1 when remote temperature sensor 2 is
out of the range defined by the upper threshold.
8
RT2-LOW-ALARM
R
0
7
RT1-HIGH-ALARM
R
0
Always zero when the remote sensor is disabled.
RT2-LOW-ALARM = 1 when remote temperature sensor 2 is out
of the range defined by the lower threshold.
Always zero when the remote sensor is disabled.
RT1-HIGH-ALARM = 1 when remote temperature sensor 1 is
out of the range defined by the upper threshold.
Always zero when the remote sensor is disabled.
6
RT1-LOW-ALARM
R
0
5
LT-HIGH-ALARM
R
0
4
LT-LOW-ALARM
R
0
RT1-LOW-ALARM = 1 when remote temperature sensor 1 is out
of the range defined by the lower threshold.
Always zero when the remote sensor is disabled.
LT-HIGH-ALARM = 1 when the local temperature sensor is out
of the range defined by the upper threshold.
Always zero when the on-chip sensor is disabled.
LT-LOW-ALARM = 1 when the local temperature sensor is out
of the range defined by the lower threshold.
Always zero when the on-chip sensor is disabled.
66
3
ADCINT4/CS4-ALARM
R
0
ADCINT4/CS4-ALARM = 1 when the ADC reading of internal
channel 4 (closed-loop) or the measurement of current sense 4
(open-loop) is out of range defined by the alarm threshold
registers.
2
ADCINT3/CS3-ALARM
R
0
ADCINT3/CS3-ALARM = 1 when the ADC reading of internal
channel 3 (closed-loop) or the measurement of current sense 3
(open-loop) is out of range defined by the alarm threshold
registers.
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Table 31. Alarm Status Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
1
ADCINT2/CS2-ALARM
R
0
ADCINT2/CS2-ALARM = 1 when the ADC reading of internal
channel 2 (closed-loop) or the measurement of current sense 2
(open-loop) is out of range defined by the alarm threshold
registers.
0
ADCINT1/CS1-ALARM
R
0
ADCINT1/CS1-ALARM = 1 when the ADC reading of internal
channel 1 (closed-loop) or the measurement of current sense 1
(open-loop) is out of range defined by the alarm threshold
registers.
7.6.7.2 General Status Register (address = 0x1F) [reset = 0x0000]
Figure 85. General Status Register (R)
15
GDAV
R-0
14
ADC-READY
R-0
13
LT-DAV
R-0
12
RT2-DAV
R-0
11
RT1-DAV
R-0
10
ADCINT-DAV
R-0
9
ADCEXT-DAV
R-0
8
CS-DAV
R-0
7
6
5
4
3
SLEEP2STATUS
R-0
2
SLEEP1STATUS
R-0
1
PAON-STATUS
0
GALARM
R-0
R-0
Reserved
R-0000
Table 32. General Status Register Field Descriptions
Bit
Field
Type
Reset
Description
15
GDAV
R
0
Global data available flag.
14
ADC-READY
R
0
ADC is ready (waiting) to be triggered. At power-up, will remain
not ready (0) until the ADC is powered up and at least one
channel is selected. If there is any write that would stop the ADC
including AMC Configuration 0, ADC MUX, or ADC alarm
threshold register writes, this bit also returns to not ready until
the device completes processing of these changes/updates,
after which time the ADC is ready to trigger again.
Goes to 0 when the ADC is triggered and is running. This bit
returns to 1 once the ADC is stopped.
13
LT-DAV
R
0
Local temperature sensor data available flag for direct-mode
conversion.
12
RT2-DAV
R
0
Remote temperature sensor 2 data available flag for direct-mode
conversion.
11
RT1-DAV
R
0
Remote temperature sensor 1 data available flag for direct-mode
conversion.
10
ADCINT-DAV
R
0
ADCINT data available flag for direct-mode conversion.
9
ADCEXT-DAV
R
0
ADCEXT data available flag for direct-mode conversion.
8
CS-DAV
R
0
Current sense data available flags for direct-mode conversion.
7-4
Reserved
R
0000
Reserved for factory use
3
SLEEP2-STATUS
R
0
Status of SLEEP2 pin.
2
SLEEP1-STATUS
R
0
Status of SLEEP1 pin.
1
PAON-STATUS
R
0
Status of PA_ON pin.
If equal to 0 the PA_ON pin is in the OFF state (PAVDD). If
equal to 1 the PA_ON pin is in the ON state (AGND).
0
GALARM
R
0
Global alarm bit.
This bit is the OR function or all individual alarm bits of the
status register. This bit is set to 1 when any alarm condition
occurs and remains set until the status register is read. This bit
is cleared after reading the Alarm Status register.
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7.6.8 ADC Data: Address 0x20 through 0x2F
7.6.8.1 ADCn-Internal-Data Register (address = 0x20 to 0x23) [reset = 0x0000]
This register description applies to the internal monitoring inputs ADCINT1 through ADCINT4.
Figure 86. ADCn-Internal-Data Register (R)
15
14
13
12
11
5
4
3
ADCINTn-DATA[7:0]
R-00h
10
9
ADCINTn-DATA[11:8]
R-0h
Reserved
R-0h
7
6
2
1
8
0
Table 33. ADCn-Internal-Data Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R
0000
Reserved for factory use.
ADCINTn-DATA[11:0]
R
0x000
Stores the 12–bit ADCINTn conversion results in straight binary
format. The corresponding voltage is given by:
11–0
Vref
§ V u DATA[11: 0]
3 ¨ ref
4096
©
·
Vref ¸
¹
(13)
7.6.8.2 ADCn-External-Data Register (address = 0x24 to 0x27) [reset = 0x0000]
This register description applies to the external inputs ADC1 through ADC4.
Figure 87. ADCn-External-Data Register (R)
15
14
13
12
11
5
4
3
ADCEXTn-DATA[7:0]
R-00h
Reserved
R-0h
7
6
10
9
ADCEXTn-DATA[11:8]
R-0h
2
1
8
0
Table 34. ADCn-External-Data Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R
0000
Reserved for factory use.
ADCEXTn-DATA[11:0]
R
0x000
Stores the 12–bit ADCn conversion results in straight binary
format.
11–0
68
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7.6.8.3 CSn-Data Register (address = 0x28 to 0x2B) [reset = 0x0000]
This register description applies to the current sense inputs CS1 through CS4.
Figure 88. CSn-Data Register (R)
15
14
13
12
11
10
9
CSn-DATA[11:8]
R-0h
8
5
4
3
2
0
Reserved
R-0h
7
6
1
CSn-DATA[7:0]
R-00h
Table 35. CSn-Data Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R
0000
Reserved for factory use.
CSn-DATA[11:0]
R
0x000
Stores the 12–bit current-sense n conversion results in straight
binary format (open-loop mode only).
11–0
7.6.8.4 LT-Data Register (address = 0x2D) [reset = 0x0000]
Figure 89. LT-Data Register (R)
15
14
13
12
11
10
Reserved
R-0h
7
6
9
8
1
0
LT-DATA[11:8]
R-0h
5
4
3
2
LT-DATA[7:0]
R-00h
Table 36. LT-Data Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R
0000
Reserved for factory use.
LT-DATA[11:0]
R
0x000
Stores the local temperature sensor reading in twos complement
format.
11–0
7.6.8.5 RTn–Data Register (address = 0x2E to 0x2F) [reset = 0x0000]
This register description applies to the remote temperature sense inputs RT1 and RT2.
Figure 90. RTn-Data Register (R)
15
14
13
12
11
10
9
RTn-DATA[11:8]
R-0h
8
5
4
3
2
0
Reserved
R-0h
7
6
1
RTn-DATA[7:0]
R-00h
Table 37. RTn–Data Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R
0000
Reserved for factory use.
RTn-DATA[11:0]
R
0x000
Stores the remote temperature sensor n (Dn+, Dn–) reading in
twos complement format.
11–0
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7.6.9 DAC Data: Address 0x30 through 0x37
7.6.9.1 DACn-Data Register (address = 0x30 to 0x33) [reset = 0x0000]
This register description applies to the bipolar DAC outputs DAC1 through DAC4.
Figure 91. DACn-Data Register (R/W)
15
14
13
12
11
5
4
3
DACn-DATA[7:0]
R/W-00h
Reserved
R/W-0h
7
6
10
9
DACn-DATA[11:8]
R/W-0h
8
2
0
1
Table 38. DACn-Data Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R/W
0000
Reserved for factory use.
DACn-DATA[11:0]
R/W
0x000
Stores the 12–bit data to be loaded to DACn in straight binary
format. The straight binary format is used for all DAC ranges.
11–0
Only active in open-loop mode.
7.6.9.2 AUXDACn-Data Register (address = 0x34 to 0x37) [reset = 0x0000]
This register description applies to the auxiliary DAC outputs AUXDAC1 through AUXDAC4.
Figure 92. AUXDACn-Data Register
15
14
13
12
11
Reserved
R/W-0h
7
6
5
4
3
AUXDACn-DATA[7:0]
R/W-00h
10
9
AUXDACn-DATA[11:8]
R/W-0h
2
1
8
0
Table 39. AUXDACn-Data Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R/W
0000
Reserved for factory use.
AUXDACn-DATA[11:0]
R/W
0x000
Stores the 12–bit data to be loaded to AUXDACn in straight
binary format. The straight binary format is used for all DAC
ranges.
11–0
70
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7.6.10 Closed-Loop Control: Address 0x38 through 0x3B
7.6.10.1 ClosedLoopn Register (address = 0x38 to 0x3B) [reset = 0x0000]
This register description applies to the ClosedLoop1 through ClosedLoop4 registers.
Figure 93. ClosedLoopn Register (R/W)
15
14
13
12
11
5
4
3
CLOSEDLOOPn[7:0]
R/W-00h
10
9
CLOSEDLOOPn[11:8]
R/W-0h
Reserved
R/W-0h
7
6
2
1
8
0
Table 40. ClosedLoopn Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R/W
0000
Reserved for factory use.
CLOSEDLOOPn[11:0]
R/W
0x000
Sets the target current for closed loop controller n through the
following equation:
11–0
I(DRAIN)
CLOSEDLOOPn >11: 0 @ u Vref
R SENSE u 51200
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7.6.11 Alarm Threshold Configuration: Address 0x40 through 0x4F
7.6.11.1 ADCINTn/CSn-Upper-Threshold Register (address = 0x40, 0x42, 0x44 and 0x46) [reset = 0x0FFF]
This register description applies to the upper threshold alarm registers for ADCINT1/CS1 through ADCINT4/CS4.
Figure 94. ADCINTn/CSn-Upper-Threshold Register (R/W)
15
14
13
12
11
Reserved
R/W-0h
7
6
5
4
3
ADCINT-CSn-UP-THRESH[7:0]
R/W-FFh
10
9
ADCINT-CSn-UP-THRESH[11:8]
R/W-Fh
2
1
8
0
Table 41. ADCINTn/CSn-Upper-Threshold Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R/W
0000
Reserved for factory use.
ADCINT-CSn-UP-THRESH[11:0]
R/W
0xFFF
Sets the 12-bit upper threshold value for the internal ADC n
(closed-loop mode) or current sense n (open-loop mode) alarm
in straight binary format as determined by the ADCINT/CSSELECT bit in register 0x1B.
11–0
7.6.11.2 ADCINTn/CSn-Lower-Threshold Register (address = 0x41, 0x43, 0x45 and 0x47) [reset = 0x0000]
This register description applies to the lower threshold alarm registers for ADCINT1/CS1 through ADCINT4/CS4.
Figure 95. ADCINTn/CSn-Lower-Threshold Register (R/W)
15
14
13
12
11
Reserved
R/W-0h
7
6
5
4
3
ADCINT-CSn-LOW-THRESH[7:0]
R/W-00h
10
9
ADCINT-CSn-LOW-THRESH[11:8]
R/W-0h
2
1
8
0
Table 42. ADCINTn/CSn-Lower-Threshold Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R/W
0000
Reserved for factory use.
ADCINT-CSn-LOW-THRESH[11:0]
R/W
0x000
Sets the 12-bit lower threshold value for the internal ADC n
(closed-loop mode) or current sense n (open-loop mode) alarm
in straight binary format.
11–0
72
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7.6.11.3 TS-Upper-Threshold Register (address = 0x48, 0x4A and 0x4C) [reset = 0x07FF]
This register description applies to the upper threshold alarm registers for the device temperature sensors: LT,
RT1 and RT2.
Figure 96. TS-Upper-Threshold Register (R/W)
15
14
13
12
11
5
4
3
TS-UP-THRESH[7:0]
R/W-FFh
Reserved
R/W-0h
7
6
10
9
TS-UP-THRESH[11:8]
R/W-7h
2
1
8
0
Table 43. TS-Upper-Threshold Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R/W
0000
Reserved for factory use.
TS-UP-THRESH[11:0]
R/W
0x7FF
Sets the 12-bit upper threshold value for the corresponding
temperature sensor (LT, RT1 or RT2) alarm in two's complement
format.
11–0
7.6.11.4 TS-Lower-Threshold Register (address = 0x49, 0x4B and 0x4D) [reset = 0x0800]
This register description applies to the lower threshold alarm registers for the device temperature sensors: LT,
RT1 and RT2.
Figure 97. TS-Lower-Threshold Register (R/W)
15
14
13
12
11
Reserved
R/W-0h
7
6
5
4
3
TS-LOW-THRESH[7:0]
R/W-00h
10
9
TS-LOW-THRESH[11:8]
R/W-8h
2
1
8
0
Table 44. TS-Lower-Threshold Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R/W
0000
Reserved for factory use.
TS-LOW-THRESH[11:0]
R/W
0x800
Sets the 12-bit lower threshold value for the corresponding
temperature sensor (LT, RT1 or RT2) alarm in two's complement
format.
11–0
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7.6.11.5 DACnn-Upper-Threshold Register (address = 0x4E and 0x4F) [reset = 0x0FFF]
This register description applies to the upper threshold alarm registers for the bipolar DAC pairs DAC1/DAC2 and
DAC3/DAC4.
Figure 98. DACnn-Upper-Threshold Register (R/W)
15
14
13
12
11
Reserved
R/W-0h
7
6
5
4
3
DACnn-UP-THRESH[7:0]
R/W-FFh
10
9
DACnn-UP-THRESH[11:8]
R/W-Fh
2
1
8
0
Table 45. DACnn-Upper-Threshold Register Field Descriptions
Bit
Field
Type
Reset
Description
15
Reserved
R/W
0000
Reserved for factory use
DACnn-UP-THRESH[11:0]
R/W
0xFFF
Sets an upper output limit othen than full-scale for the bipolar
DAC pairs (DAC1/DAC2 or DAC3/DAC4). When either of the
DACs in a given pair is loaded with a value exceeding the limit,
its output is updated with the DACnn-UP-THRESH[11:0] value
instead.
11–0
74
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7.6.12 Alarm Hysteresis Configuration: Address 0x50 and 0x56
7.6.12.1 ADCINTn/CSn-Hysteresis Register (address = 0x50 to 0x53) [reset = 0x0008]
This register description applies to the hysteresis registers for ADCINT1/CS1 through ADCINT4/CS4.
Figure 99. ADCINTn/CSn-Hysteresis Register (R/W)
15
14
13
12
11
10
9
8
3
ADCINT-CSn-HYSTER[6:0]
R/W-08h
2
1
0
Reserved
R/W-00h
7
Reserved
R/W-0
6
5
4
Table 46. ADCINTn/CSn-Hysteresis Register Field Descriptions
Field
Type
Reset
Description
15–7
Bit
Reserved
R/W
All zeros
Reserved for factory use.
6–0
ADCINT-CSn-HYSTER[6:0]
R/W
0x08
Hysteresis of internal ADC n (closed-loop mode) or current
sense n (open-loop mode), 1 LSB per step.
7.6.12.2 LT-Hysteresis Register (address = 0x54) [reset = 0x0008]
Figure 100. LT-Hysteresis Register (R/W)
15
14
13
12
11
10
9
8
3
2
LT -HYSTER[4:0]
R/W-08h
1
0
Reserved
R/W-00h
7
6
Reserved
R/W-0h
5
4
Table 47. LT-Hysteresis Register Field Descriptions
Bit
Field
Type
Reset
Description
15–5
Reserved
R/W
All zeros
Reserved for factory use
4–0
LT -HYSTER[4:0]
R/W
0x08
Hysteresis of local temperature sensor, 1°C per step.
7.6.12.3 RTn–Hysteresis Register (address = 0x55 to 0x56) [reset = 0x0008]
This register description applies to the hysteresis registers for RT1 and RT2.
Figure 101. RTn–Hysteresis Register (R/W)
15
14
13
12
11
10
9
8
3
2
RTn-HYSTER[4:0]
R/W-08h
1
0
Reserved
R/W-00h
7
6
Reserved
R/W-0h
5
4
Table 48. RTn–Hysteresis Field Descriptions
Bit
Field
Type
Reset
Description
15–5
Reserved
R/W
All zeros
Reserved for factory use
4–0
RTn-HYSTER[4:0]
R/W
0x08
Hysteresis of remote temperature sensor n (Dn+, Dn–), 1°C per
step.
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7.6.13 GPIO: Address 0x58
7.6.13.1 GPIO Register (address = 0x58) [reset = 0x000F]
Figure 102. GPIO Register (R/W)
15
14
13
12
11
10
9
8
3
GPIO4
R/W-1
2
GPIO3
R/W-1
1
GPIO2
R/W-1
0
GPIO1
R/W-1
Reserved
R/W-00h
7
6
5
4
Reserved
R/W-0h
Table 49. GPIO Register Field Descriptions
Bit
Field
Type
Reset
Description
Reserved
R/W
All zeros
Reserved for factory use
3
GPIO4
R/W
1
2
GPIO3
R/W
1
1
GPIO2
R/W
1
For write operations the GPIO pin operates as an output. Writing
a 1 to the GPIOn bit sets the GPIOn pin to high impedance.
Writing a 0 sets the GPIOn pin to logic low. An external pullup
resistor is required when using the GPIO as an output.
0
GPIO1
R/W
1
15-4
For read operations the GPIO pin operates as an input. Read
the GPIOn bit to receive the status of the GPIOn pin.
After power-on reset, or any forced hardware or software reset,
the GPIOn pin is in a high-impedance state.
76
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8 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
The AMC7834 device is a highly integrated, low-power, analog monitoring and control solution that includes one
multi-channel 12-bit ADC, eight 12-bit DACs, four high-side current-sense amplifiers and temperature sensing
capabilities. The AMC7834 typical application is power amplifier biasing in wireless base stations, however its
high level integration make it a good solution for many different systems ranging from industrial control sytems to
test-and-measurement units.
The power amplifiers (PAs) used in wireless infrastructure include transistor technologies that are extremely
temperature sensitive, and require DC biasing circuits to optimize RF performance, power efficiency, and
stability. The AMC7834 device provides eight DAC channels that can be used to bias the inputs of the power
amplifiers. The device also includes two remote temperature sensing interfaces, one internal local temperature
sensor, four high-side current-sensing channels, and four ADC channels for general-purpose monitoring.
Current sensing and temperature sensing are the two main monitoring schemes for PA bias compensation. The
PA drain current is monitored by measuring the differential voltage drop accross a shunt resistor. The AMC7834
internal local-temperature sensor and two remote-sensor driver inputs can be used to detect temperature
variations during PA operation. Figure 103 shows the circuit diagram of this system.
AMC7834
Analog Inputs
GPIO
CS
PA Drain Voltage
Current Sense
SENSE1+
MUX
ADC
CS
R(SENSE)
VSENSE Current Sensing
SENSE1±
Local
Temperature
RF Out
D1+
Remote
Temperature
Temperature Sensing
D1±
Bipolar
Analog Outputs
Drain
Gate
DAC
Source
Unipolar
Analog Outputs
AUX
DAC
Power Amplifier
RF In
Figure 103. AMC7834 Example PA Bias System
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8.2 Typical Application
External Temperature
Diodes
ADC BLOCK
AVDD
AGND4
44
43
DGND
SENSE
Resistor 4
AVDD
AVDD
DAC4
28
DAC3
AVDD1
AVSS
30
VCLAMP2 29
27
DAC2
DAC1
AGND2
VCLAMP1
22
23
24
25
26
REF_OUT
DVDD
SENSE
Resistor 3
SENSE4±
IOVDD
0.1 µF
GND
AVDD2
SENSE3±
AGND1
0.1 µF
SDO
14 AV
CC
SENSE
Resistor 2
34
33
32
SENSE4+
31
SENSE3+
15
16 AUXDAC1
13
AVCC
PA ON
SENSE
Resistor 1
AGND3 35
SDI
18
AUXDAC3
19
AUXDAC4
20
REF_IN
21
DVDD
0.1 µF
40
SENSE2±
CS
17
IOVDD
42
41
39
38
SENSE1±
37
SENSE2+
36
Thermal Pad
AUXDAC2
8
9
10
11
12
PA_ON
4.7 µF
SENSE1+
SCLK
CS
SDI
SDO
PAVDD
AMC7834
3 SLEEP1
4 SLEEP2
5 RESET
6
DACTRIG
7
DACTRIG
SCLK
ADC4
49
48
47
ADC2
46
ADC3
45
D2-
REF_CMP
ALARMOUT
SLEEP2
RESET
ADC1
51
50
D1-
D2+
53
52
1
DAV/ADC_RDY
2
DAV/ADC_RDY
ALARMOUT
SLEEP1
D1+
GPIO4
GPIO3
GPIO2
GPIO1
10 k
56
55
54
0.1 µF
10 k:
10 k
10 k
10 k
Digital Control
100 pF
100 pF
10 k
10 k
10 k
10 k
IOVDD
GPIO
AVSS
IOVDD
R1
R3
R2
R4
VCLAMP
Settings
PAVDD
AVDD
10 nF
0.1 µF
SENSE 1+
SENSE 1±
AVSS
0.1 µF
Vg1
DAC Outputs
Vg6
Vg5
Vg7
Vg8
Range 1
Vg1
Vg2
Vg3
SENSE
resistor 1
Power Amplifier
Connect Analog
and Digital GNDs
Example connection using DAC output
(Vg1) and the SENSE1r connection
Vg4
Range 2
Figure 104. AMC7834 Example Schematic
8.2.1 Design Requirements
The AMC7834 example schematic uses the majority of the design parameters listed in Table 50.
Table 50. Design Parameters
DESIGN PARAMETER
78
EXAMPLE VALUE
AVCC
5V
IOVDD
3.3 V
DVDD
5V
AVDD
5V
AVSS
–5 V
4 External unipolar inputs
ADC[1-4]: 0 to 2.5 V range
4 High-Side Current Sense
Differential input of 0 to 200 mV
4 bipolar DAC outputs
–4 to 1 V, –5 to 0 V, and 0 to 5 V
4 unipolar DAC outputs
0 to 5 V, 2.5 to 7.5 V
Remote temperature sensing
Two remote temperature diode drivers
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8.2.2 Detailed Design Procedure
Use the following parameters to facilitate the design process:
• AVCC and AVSS voltage values
• ADC and high-side current-sense input voltage range
• DAC output voltage ranges
• Remote temperature applications
8.2.2.1 ADC Input Conditioning
The AMC7834 monitoring system is centered on a single ADC core that features a multichannel input stage to a
successive approximation register (SAR) ADC. The analog inputs include four external analog inputs, four
internal inputs for bipolar DAC monitoring, four high-side current-sense amplifiers for PA current monitoring, two
remote temperature sensors, and an internal analog temperature sensor.
The external analog inputs (ADC1 through ADC4) feature a range of 0 to Vref (Vref corresponds to either an
external 2.5 V reference or the device internal reference), while the internal inputs accept a full-scale range of –5
to 2.5 V. The current-sense inputs feature a 4 to 60 V common-mode voltage range, and accept a differential
input range of 0 to 200 mV. A 4.7 µF capacitor is recommended between the REF_CMP pin and the AGND4 pin.
The value of this capacitor must exceed 470 nF to ensure reference stability. A high-quality ceramic capacitor,
type NP0 or X7R, is recommended because of the optimal performance of the capacitor across temperature and
very-low dissipation factor.
It is recommended that all external analog inputs are driven with a low impedance source to ensure correct
functionality. In applications where the signal-source impedance is high, the analog inputs can be conditioned
through a buffer amplifier, such as a voltage follower.
8.2.2.2 DAC Output Range Selection
The AMC7834 device has four bipolar and four unipolar DACs with programmable output ranges. The bipolar
DACs feature the ranges –4 to 1 V, –5 to 0 V, and 0 to 5 V. The unipolar DACs feature the ranges 0 to 5 V and
2.5 to 7.5 V. The DAC ranges are configurable by setting the DAC range register (see the DAC Range Register
(address = 0x16) [reset = 0x0000] section).
The maximum source and sink capability of the DAC internal amplifiers are listed as part of the DAC output
characteristics in the Electrical Characteristics—DAC Specifications table.
The graph in the Application Performance Curve section show the relationship of both stability and settling time
with different capacitive and resistive loading structures.
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8.2.2.3 Temperature Sensing Applications
The AMC7834 has one local temperature and two temperature diode drivers, as well as four external analog
inputs that are easily configurable to remote temperature sensor circuits. The integrated temperature sensor,
remote temperature sensor, and analog input registers automatically update with every conversion. Figure 105
shows a typical setup for the two temperature diode-driver inputs. Additional noise filtering can be achieved by
placing a bypass capacitor across the inputs of the remote temperature sensors. A high-quality ceramic
capacitor, type NP0 or X7R, is recommended because of the optimal performance of the capacitor across
temperature. See the Remote Temperature Sensors section for a details.
PNP
D+
100 pF
D±
Temperature diodes
on PA board
D+
100 pF
D±
NPN
Figure 105. Remote Temperature Sensors (PNP and NPN)
Additionally, the ADC inputs can be used to accept voltage from other temperature-sensing IC circuits as shown
in Figure 106. The temperature sensor use for analog input conditioning in this example is the LM50 device
which is a high precision integrated-circuit temperature sensor that can sense a –40°C to +125°C temperature
range using a single positive supply. The full-scale output of the temperature sensor ranges from 100 mV to 1.75
V for a –40°C to +125°C temperature range. In an extremely noisy environment, adding some filtering to
minimize noise pickup may be necessary. A typical recommended value for the bypass capacitor is 0.1 µF from
the V+ pin to ground. A high-quality ceramic capacitor, type NP0 or X7R, is recommended because of the
optimal performance of the capacitor across temperature and very-low dissipation factor.
DVDD
4
V+
LM50
VO
NC
3
ADC4
1
GND
0.1 µF
2
5
Figure 106. Temperature Sense Application With LM50
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8.2.2.4 Current Sensing Applications
The AMC7834 device also features four high-side current-sense amplifiers that support common-mode voltages
from 4 to 60 V and a full-scale sense voltage of 0 to 200 mV. In applications that require current sensing across
a power amplifier, the SENSE± differential inputs connect across a resistor to sense small differential voltage that
is proportional to current across the PA as shown in Figure 107. The current-sense conversion results are stored
in the Current sense data registers. The current sensors are also configurable as closed-loop drain current
controllers. See the Current Sensors section for details.
Figure 107 shows a method of separating the drain voltage from the power amplifier with a series PMOS
transistor. The activation of the PMOS connects the PAVDD voltage supply to the drain pin of the power amplifier.
The PMOS is driven with a voltage divider that swings from PAVDD to PAVDD(R2 / [R1 + R2]). The NMOS shown
in Figure 107 is connected to the PA_ON output which controls the state of the PMOS transistor.
PA Drain Voltage
SENSE1+
R(SENSE)
R1
ûV = IDS u R(SENSE)
SENSE1±
PMOS
R2
IDS
NMOS
PA ON
Drain
Gate
DAC Voltage
Source
Power Amplifier
Figure 107. Current Sense (SENSE) Connections With PMOS ON and OFF
8.2.3 Application Performance Curve
50
100pF
200pF
1nF
10nF
DAC Ouput Error (mV)
40
30
20
10
0
-10
-20
-30
-40
-50
0
5
10
15
20
25
Time ( s)
30
C023
Code 0x000 to 0xFFF to within 0.5% of final value
Figure 108. DAC Settling Time
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8.3 Initialization Set Up
8.3.1 Initialization Procedure
1. Supply all voltages (PAVDD, AVDD, DVDD, IOVDD, AVCC, AVSS) and clamp inputs (VCLAMP1 and VCLAMP2).
The AMC7834 does not require a specific supply sequencing.
2. A 250 µs POR delay occurs after a minimum AVDD supply of 4.5 V has been applied. Do not attempt serial
communication during this time.
3. It is recommended to issue a hardware or software-reset.
4. Wait for completion of the reset operation (at least 250 µs for a hardware reset or at least 10 µs for a
software reset).
5. After reset, the following conditions are met:
– The device is in open-loop mode and all DAC data registers are set to all zeros.
– All DAC outputs are set to the clamp value regardless of the SLEEP1 and SLEEP2 pin levels.
– The PA_ON signal is set to the OFF state.
6. If not already done so, it is recommended to tie the SLEEP1 and SLEEP2 pins low.
7. Configure the AMC7834 without the DACs leaving clamp mode.
8. If the PA_ON control signal is enabled, switch the PA_ON signal to the ON state. By default, the AVSS supply
must be present to enable the PA_ON signal to enter the ON state.
9. Release the DACs out of clamp mode.
10. Verify that the ADC has entered the READY state.
11. Issue an ADC trigger signal to initiate conversion of the monitoring inputs.
After initialization the AMC7834 allows switching between open-loop and closed-loop operation. However, before
switching between operating modes, it is strongly recommended to clamp the bipolar DAC outputs, stop the ADC
conversion cycle, and if applicable, switch the PA_ON signal to the OFF state. To resume operation follow steps
7 through 11 of the Initialization Procedure.
9 Power Supply Recommendations
The AMC7834 supply voltage ranges are specified in the Recommended Operating Conditions table.
10 Layout
10.1 Layout Guidelines
•
•
•
•
82
All power supply pins should be bypassed to ground with a low-ESR ceramic bypass capacitor. The typical
recommended bypass capacitance has a value of 0.1 µF and is ceramic with a X7R or NP0 dielectric.
A 4.7 µF capacitor is recommended between the REF_CMP pin and the AGND4 pin. A minimum capacitor
value of 470 nF is required to ensure stability.
A high-quality ceramic capacitor, type NP0 or X7R, is recommended because of the optimal performance of
the capacitor across temperature and very-low dissipation factor.
The digital and analog sections should have proper placement with respect to the digital pins and analog pins
of the AMC7834 device (see Figure 110). The separation of analog and digital blocks allows for better design
and practice as it ensures less coupling into neighboring blocks and minimizes the interaction between analog
and digital return currents.
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43
44 AVDD2
45 ADC4
46 ADC3
47 ADC2
48 ADC1
49 D2±
50 D2+
51 D1±
52 D1+
53 GPIO4
54 GPIO3
42
ALARMOUT
2
41 PAVDD
REF_CMP
PAVDD tied to AVDD
internal plane
SLEEP1
3
40 PA_ON
SLEEP2
4
39 SENSE1+
RESET
5
38 SENSE1±
DACTRIG
6
SCLK
7
CS
8
35 AGND3
SDI
9
34 SENSE3+
SDO 10
33 SENSE3±
DGND 11
32 SENSE4+
IOVDD 12
31 SENSE4±
DVDD 13
30 VCLAMP1
AVCC 14
29 VCLAMP2
37 SENSE2+
36 SENSE2±
DAC4 28
AVDD1 26
0.1 µF
DAC3 27
AVSS 25
0.1 µF
DAC2 24
DAC1 23
AGND2 22
REFOUT 21
10 nF
REFIN 20
AUXDAC4 19
AUXDAC3 18
AMC7834
AUXDAC1 15
0.1 µF
4.7 µF
1
AGND1 17
0.1 µF
AGND4
DAV/ADC_RDY
AUXDAC2 16
0.1 µF
55 GPIO2
56 GPIO1
0.1 µF
10.2 Layout Example
Figure 109. AMC7834 Layout Example
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43
44
45
46
47
48
49
50
51
52
53
54
55
56
1
42
2
41
3
40
4
39
5
38
6
37
7
36
AMC7834
8
35
28
27
26
25
24
23
22
21
29
20
30
14
19
31
13
18
32
12
17
33
11
16
34
10
15
9
ANALOG
DIGITAL
Layout Example (continued)
Figure 110. AMC7834 Example Board Layout — Component Placement
84
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11 Device and Documentation Support
11.1 Documentation Support
11.1.1 Related Documentation
For related documentation see the following:
• LM50/LM50-Q1 SOT-23 Single-Supply Centigrade Temperature Sensor, SNIS118
• LMP848x Precision 76-V High-Side Current Sense Amplifiers With Voltage Output, SNVS829
11.2 Community Resources
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
11.3 Trademarks
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
11.4 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
11.5 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
12 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
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PACKAGE OPTION ADDENDUM
www.ti.com
30-Sep-2021
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
AMC7834IRTQR
ACTIVE
QFN
RTQ
56
2000
RoHS & Green NIPDAU | NIPDAUAG
Level-3-260C-168 HR
-40 to 125
AMC7834
AMC7834IRTQT
ACTIVE
QFN
RTQ
56
250
RoHS & Green
Level-3-260C-168 HR
-40 to 125
AMC7834
NIPDAU
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of