ATSENSE-101/ATSENSE-201(H)/
ATSENSE-301(H)
Multi-Channel Sigma-Delta Analog Front End
Description
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H) are multi-channel analog front end devices which integrate three,
four or seven simultaneously sampled Sigma-Delta A/D converters, a high-precision voltage reference with up to 10
ppm/°C temperature stability (H-versions), a programmable current signal amplification, a temperature sensor and an
SPI interface. When used in data acquisition and energy measurement applications in combination with the Microchip
ATSAM4C device family that features a dedicated Cortex®-M4 processor and metrology library and a variety of sensors
including Shunt, CT and Rogowski coils, the ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H) exceeds ANSI
C12.20-2002 and IEC 62053-22 metering accuracy classes of up to 0.2% over 3000:1 current range.
Features
• Analog Front End
- Single-phase (ATSENSE-101), Dual-phase (ATSENSE-201(H)) or Poly-phase (ATSENSE-301(H)) Energy
Metering Analog Front End Suitable for Microchip MCUs and Metrology Library
- Compliant with Class 0.2 Standards (ANSI C12.20-2002 and IEC 62053-22)
- Three, Four or Seven Sigma-Delta ADC Measurement Channels: One, Two or Three Voltages, Two or Four Currents, 102 dB Dynamic Range
- Current Channels with Pre-Gain (x1, x2, x4, x8)
- Supports Shunt, Current Transformer and Rogowski Coils
- Dedicated Current Channel for Anti-tamper Measurement
- Integrated SINC Decimation Filters. Output Data Rate: 16 kSps typical
- Integrated 2.8V LDO Regulator to Supply Analog Functions
- 3.0V to 3.6V Operation, Ultra Low Power: < 2.5 mW typical/Channel @ 3.3V
- Specified over two ambient operating temperature ranges : [-40°C ; +85°C] and [-40°C;+105°C]
• Precision Voltage Reference
- Standard 1.2V Output Voltage with Possible External Bypass
- Temperature Drift: 50 ppm typical (ATSENSE-101/ATSENSE-201/ATSENSE-301)
- Temperature Drift: 10 ppm typical (ATSENSE-201H/ATSENSE-301H)
- Factory-measured Temperature Drift and Die Temperature Sensor to Perform Software Correction
- Digital Interface
- 8 MHz Serial Peripheral Interface (SPI) Compatible Mode 1 (8-bit) for ADC Data and AFE Controls
- Interrupt Output Line Signaling ADC End-of-Conversion, Underrun and Overrun
• Package
- 32-lead TQFP, 7 x 7 x 1.4 mm
- 20-lead SOIC, 12.8 x 7.5 x 2.3 mm
2017 Microchip Technology Inc.
DS60001524A-page 1
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H)
1.
Block Diagrams
ATSENSE-301(H) Functional Block Diagram
VD
D
G A
N
D
VR A
EF
Figure 1-1:
VDDA
VP3
ΣΔ ADC
VN
VD
D
G A
N
D
VR A
EF
Decimator
VDDIN
Decimator
ΣΔ ADC
PGA
2.8V
LDO
ADCI3
IP3
IN3
GNDA
ADCV3
Die
Temperature
sensor
VREF
Voltage
Reference 500Ω
VD
D
G A
N
D
VR A
EF
GNDREF
VTEMP
VP2
ΣΔ ADC
VN
VD
D
G A
N
D
VR A
EF
Decimator
IN2
SPCK
Serial
Peripheral
Interface
ADCI2
IP2
Decimator
ΣΔ ADC
PGA
ADCV2
NPCS
MISO
MOSI
VD
D
G A
N
D
VR A
EF
Control
Registers
Interrupt
Controller
VP1
ΣΔ ADC
VN
VD
D
G A
N
D
VR A
EF
Decimator
PGA
ROM
(Calibration Data)
ADCI1
IP1
IN1
ADCV1
ITOUT
Decimator
ΣΔ ADC
VDDT
VDDIO
FS_CLK
(MCLK/OSR)
ADC_CLK
(MCLK/2)
VD
D
G A
N
D
VR A
EF
IP0
PGA
ΣΔ ADC
GNDD
MCLK
ADCI0
IN0
DIFF
MUX
2:1
Power
Clock
Generator On Reset
Decimator
VTEMP
ATSENSE-301(H)
DS60001524A-page 2
2017 Microchip Technology Inc.
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H)
Figure 1-2:
ATSENSE-201(H) Functional Block Diagram
VDDIN
2.8V
LDO
VDDA
Die
Temperature
sensor
Voltage
Reference
GNDA
500Ω
VD
D
G A
N
D
VR A
EF
VTEMP
VP2
ΣΔ ADC
Decimator
VREF
GNDREF
ADCV2
VN
VD
D
G A
N
D
VR A
EF
SPCK
Serial
Peripheral
Interface
VP1
ΣΔ ADC
VN
VD
D
G A
N
D
VR A
EF
Decimator
PGA
MISO
MOSI
Control
Registers
ADCI1
IP1
IN1
ADCV1
NPCS
Decimator
ΣΔ ADC
Interrupt
Controller
ITOUT
ROM
(Calibration Data)
VD
D
G A
N
D
VR A
EF
IP0
VDDT
ADCI0
IN0
DIFF
MUX
2:1
PGA
ΣΔ ADC
Decimator
VDDIO
FS_CLK
(MCLK/OSR)
ADC_CLK
(MCLK/2)
Power
Clock
Generator On Reset
GNDD
VTEMP
MCLK
ATSENSE-201(H)
2017 Microchip Technology Inc.
DS60001524A-page 3
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H)
Figure 1-3:
ATSENSE-101 Functional Block Diagram
VDDIN
2.8V
LDO
VDDA
Die
Temperature
sensor
Voltage
Reference
GNDA
500Ω VREF
VTEMP
VD
D
G A
N
D
VR A
EF
GNDREF
SPCK
VP1
ΣΔ ADC
VN
VD
D
G A
N
D
VR A
EF
Decimator
ADCI1
IP1
PGA
IN1
Serial
Peripheral
Interface
ADCV1
Interrupt
Controller
VTEMP
PGA
ΣΔ ADC
ITOUT
VDDT
ADCI0
IN0
DIFF
MUX
2:1
MOSI
ROM
(Calibration Data)
VD
D
G A
N
D
VR A
EF
IP0
MISO
Control
Registers
Decimator
ΣΔ ADC
NPCS
Decimator
VDDIO
FS_CLK
(MCLK/OSR)
ADC_CLK
(MCLK/2)
Power
Clock
Generator On Reset
GNDD
MCLK
ATSENSE-101
DS60001524A-page 4
2017 Microchip Technology Inc.
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H)
2.
Package and Pinout
2.1
ATSENSE-201(H) / ATSENSE-301(H)
Table 2-1:
24
23
22
21
20
19
18
17
GNDD
VDDIO
-
-
-
-
-
-
32-lead LQFP Package
25
ITOUT
26
SPCK
27
MOSI
28
MISO
29
NPCS
30
MCLK
31
VDDT
32
VDDIN
VP2
VP1
VN
VREF
GNDREF
GNDA
VDDA
ATSENSE-201(H)
ATSENSE-301(H)
VP3
Figure 2-1:
1
2
3
4
5
6
7
8
IP0
16
IN0
15
IP1
14
IN1
13
IP2
12
IN2
11
IP3
10
IN3
9
ATSENSE-201(H) / ATSENSE-301(H) Pin Description
Pin Name
I/O
Pin Number
Type
(1)
Function
VP3
Input
1
Analog
Voltage channel 3, positive input
VP2
Input
2
Analog
Voltage channel 2, positive input
VP1
Input
3
Analog
Voltage channel 1, positive input
VN
Input
4
Analog
Voltage channels negative input
VREF
In / Out
5
Analog
Voltage reference output and ADCs reference buffer input
GNDREF
Ground
6
Ground
Voltage reference ground pin
GNDA
Ground
7
Ground
Ground pin for low noise analog circuits and low noise
negative ADC reference
VDDA
In / Out
8
Analog
2.8V LDO output and analog circuits power supply input
(1)
Input
9
Analog
Current channel 3, negative input
(1)
Input
10
Analog
Current channel 3, positive input
IN2(1)
Input
11
Analog
Current channel 2, negative input
(1)
Input
12
Analog
Current channel 2, positive input
IN1
Input
13
Analog
Current channel 1, negative input
IP1
Input
14
Analog
Current channel 1, positive input
IN0
Input
15
Analog
Current channel 0 (Tamper), negative input
IP0
Input
16
Analog
Current channel 0 (Tamper), positive input
-
17 .. 22
-
VDDIO
Input
23
Power
Power supply input pin for digital I/O and digital core
circuits
GNDD
Ground
24
Ground
Ground pin for digital I/O and digital core circuits
IN3
IP3
IP2
-
2017 Microchip Technology Inc.
Not connected. Connect to ground
DS60001524A-page 5
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H)
Table 2-1:
ATSENSE-201(H) / ATSENSE-301(H) Pin Description (Continued)
Pin Name
I/O
Pin Number
Type
Function
ITOUT
Output
25
Digital
Interrupt output line. Open-drain
SPCK
Input
26
Digital
SPI port: serial clock
MOSI
Input
27
Digital
SPI port: master output slave input
MISO
Output
28
Digital
SPI port: master input slave output
NPCS
Input
29
Digital
SPI port: active-low chip select
MCLK
Input
30
Digital
Master clock input
VDDT
Input
31
Power
Pin reserved for test. Connect to VDDIN / VDDIO plane
VDDIN
Input
32
Power
2.8V LDO power supply input pin
Note
1: Only in ATSENSE-301(H) devices. In ATSENSE-201(H) devices, these pins are not internally connected and Microchip
recommends to connect them to ground.
DS60001524A-page 6
2017 Microchip Technology Inc.
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H)
ATSENSE-101
20-lead SOIC Package
13
17
12
11
IP1
18
14
IN0
15
19
IP0
16
20
MOSI
17
SPCK
18
ITOUT
19
VDDIO
NPCS
20
MISO
Figure 2-2:
GNDD
2.2
Table 2-2:
Pin Name
MCLK
VDDT
VDDIN
VP1
VN
VREF
GNDREF
GNDA
VDDA
IN1
ATSENSE-101
1
2
3
4
5
6
7
8
9
10
ATSENSE-101 Pin Description
I/O
Pin Number
Type
Function
MCLK
Input
1
Digital
Master clock Input
VDDT
Input
2
Power
Pin reserved for test. Connect to VDDIN / VDDIO plane
VDDIN
Input
3
Power
2.8V LDO Power supply input pin
VP1
Input
4
Analog
Voltage channel 1, positive input
VN
Input
5
Analog
Voltage channel negative input
VREF
In / Out
6
Analog
Voltage reference output and ADCs reference buffer
input
GNDREF
Ground
7
Ground
Voltage reference ground pin
GNDA
Ground
8
Ground
Ground pin for low noise analog circuits and low noise
negative ADC reference
VDDA
In / Out
9
Analog
2.8V LDO output and analog circuits power supply input
IN1
Input
10
Analog
Current channel 1, negative input
IP1
Input
11
Analog
Current channel 1, positive input
IN0
Input
12
Analog
Current channel 0 (Tamper), negative input
IP0
Input
13
Analog
Current channel 0 (Tamper), positive input
MOSI
Input
14
Digital
SPI port: master output slave input
SPCK
Input
15
Digital
SPI port: serial clock
ITOUT
Output
16
Digital
Interrupt output line. open drain
VDDIO
Input
17
Power
Power supply input pin for digital I/O and digital core
circuits
GNDD
Ground
18
Ground
Ground pin for digital I/O and digital core circuits
MISO
Output
19
Digital
SPI port: master input slave output
NPCS
Input
20
Digital
SPI port: active-low chip select
2017 Microchip Technology Inc.
DS60001524A-page 7
DS60001524A-page 8
C.T
2000:1
L3
N
Shunt
150μR
3k
3k
3.3nF
3.3nF
3.3nF
1.5
3k
3.3nF
1.5
3k
165k (x10)
1k
3.3nF
3k
3.3nF
1.5
1k
1.5
3k
165k (x10)
3.3nF
3k
3.3nF
1.5
1k
1.5
3k
165k (x10)
2.2k
2.2k
2.2k
3.3nF
3.3nF
3.3nF
IN0
IP0
IN1
IP1
VN
VP1
IN2
IP2
VN
VP2
IN3
IP3
VN
VP3
VTEMP
A A
D ND EF
VD G VR
DIFF
MUX
2:1
PGA
A A
D ND EF
VD G VR
A A
D ND EF
VD G VR
ΣΔ ADC
A A
D ND EF
VD G VR
Decimator
Decimator
Decimator
Decimator
Decimator
Decimator
Decimator
ADCI0
ADCI1
ADCV1
ADCI2
ADCV2
ADCI3
ADCV3
FS_CLK
(MCLK/2)
ADC_CLK
(MCLK/OSR)
Interrupt
Controller
Control
Registers
Serial
Peripheral
Interface
Voltage
Reference
VREF
VDDIN
VDDT
MCLK
GNDD
VDDIO
ATSENSE-301(H)
Power
Clock
Generator On Reset
ITOUT
MOSI
MISO
NPCS
SPCK
GNDREF
500Ω
ROM
(Calibration Data)
VTEMP
Die
Temperature
sensor
2.8V
LDO
VDDA
GNDA
1μF
1μF
Typical 200A (Imax), 3-phase, 4-Wire Smart Meter
based on Microchip Metrology Solution
PGA
ΣΔ ADC
A A
D ND EF
VD G VR
ΣΔ ADC
ΣΔ ADC
PGA
A A
D ND EF
VD G VR
ΣΔ ADC
ΣΔ ADC
PGA
ΣΔ ADC
A A
D ND EF
VD G VR
1μF
VARh
100
PIOs
SPI
Wh
100
32.768kHz
Microchip MCU
VDDIO
VDD 3.3V
Figure 3-1:
C.T
2000:1
L2
3.
C.T
2000:1
L1
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H)
Application Block Diagram
ATSENSE-301(H) Typical Application Block Diagram
2017 Microchip Technology Inc.
2017 Microchip Technology Inc.
C.T
2000:1
C.T
2000:1
L2
N
3.3nF
1.5
3.3k
3.3nF
1.5
3.3k
3.3nF
1.5
3.3k
3.3nF
1.5
3.3k
165k (x10)
165k (x10)
2.2k
1k
2.2k
1k
3.3nF
3.3nF
IN0
IP0
IN1
IP1
VN
VP1
VN
VP2
VTEMP
ΣΔ ADC
VD
D
GN A
D
VR A
EF
DIFF
MUX
2:1
PGA
VD
D
GN A
D
VR A
EF
ΣΔ ADC
V
D
D
GN A
D
VR A
EF
Decimator
Decimator
Decimator
Decimator
2.8V
LDO
VDDIN
ADCI0
ADCI1
ADCV1
ADCV2
VTEMP
500Ω
Clock
Generator
Power
On Reset
ROM
(Calibration Data)
Interrupt
Controller
Control
Registers
Serial
Peripheral
Interface
Voltage
Reference
VDDA
VREF
GNDA
MCLK
GNDD
VDDIO
VDDT
ITOUT
MOSI
MISO
NPCS
SPCK
GNDREF
ATSENSE-201(H)
(MCLK/2)
ADC_CLK
(MCLK/OSR)
FS_CLK
Die
Temperature
sensor
Typical 100A (Imax), Dual-phase Smart Meter
based on Microchip Metrology Solution
PGA
ΣΔ ADC
ΣΔ ADC
D
GN A
D
VR A
EF
1μF
1μF
1μF
VARh
100
PIOs
SPI
Wh
100
32.768 kHz
Microchip MCU
VDDIO
VDD 3.3V
Figure 3-2:
VD
L1
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H)
ATSENSE-201(H) Typical Application Block Diagram
DS60001524A-page 9
N
DS60001524A-page 10
Shunt
150uR
3.3k
3.3k
3.3nF
3.3nF
3.3nF
1.5
3.3k
3.3nF
1.5
3.3k
165k (x10)
2.2k
1k
3.3nF
IN0
IP0
IN1
IP1
VN
VP1
PGA
ΣD ADC
A A
D ND EF
VD G VR
ΣD ADC
A A
D ND EF
VD G VR
Decimator
Decimator
Decimator
ADCI0
ADCI1
ADCV1
FS_CLK
(MCLK/2)
ADC_CLK
ROM
(Calibration Data)
ATSENSE-101
Power
Clock
Generator On Reset
VDDA
VREF
GNDA
MCLK
GNDD
VDDIO
VDDT
ITOUT
MOSI
MISO
NPCS
SPCK
GNDREF
500Ω
Interrupt
Controller
Control
Registers
Serial
Peripheral
Interface
Voltage
Reference
(MCLK/OSR)
VTEMP
Die
Temperature
sensor
1μF
1μF
1μF
VARh
100
PIOs
SPI
Typical 100A (Imax), Single-phase with anti-tamper Smart Meter
based on Microchip Metrology Solution
VTEMP
DIFF
MUX
2:1
PGA
ΣD ADC
A A
D ND EF
VD G VR
2.8V
LDO
VDDIN
Wh
100
32.768 kHz
Microchip MCU
VDDIO
VDD 3.3V
Figure 3-3:
C.T
2000:1
L
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H)
ATSENSE-101 Typical Application Block Diagram
2017 Microchip Technology Inc.
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H)
4.
Functional Description
4.1
Conversion Channels
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H) devices feature three types of acquisition channels:
• Voltage channels
• Current channels
• Tamper and temperature channels
All these channels are built around the same Sigma-Delta A/D converter. The voltage reference of this converter is the VREF pin voltage
referred to ground (GNDA pin). This reference voltage can be internally or externally sourced. The converter sampling rate is MCLK/4,
typically 1.024 MHz. An external low-pass filter, typically a passive R-C network, is required at each ADC input to reject frequency images
around this sampling frequency (anti-alias).
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H) analog inputs are designed to sample 0V centered signals. As these inputs have
internal ESD protection devices connected to GNDA, the maximum input signal level defined in the electrical characteristics, typically
±0.25V, must be respected to avoid leakage in these devices.
Refer to Figure 4-1, "Analog Inputs: Recommended Input Range".
Figure 4-1:
Analog Inputs: Recommended Input Range
VDDA
+0.25V
E.S.D
IPx
V(IPx,GND)
(0.5Vpp)
E.S.D
-0.25V
GNDA
+0.5V
V(IPx,VINx)
(1Vpp)
VDDA
+0.25V
-0.5V
“Current”
Acquisition
Channel
E.S.D
INx
V(INx,GND)
(0.5Vpp)
E.S.D
-0.25V
GNDA
VDDA
+0.25V
E.S.D
VPx
V(VPx,GND)
(0.5Vpp)
E.S.D
-0.25V
GNDA
+0.25V
V(VPx,VN)
(0.5Vpp)
VDDA
-0.25V
“Voltage”
Acquisition
Channel
E.S.D
VN
GND
E.S.D
GNDA
Voltage channels have single-ended inputs referred to the VN pin. The VN pin must be connected to a low noise ground. The user must
take care that no voltage drop on the ground net is sampled by the ADC by non-optimum connection of the VN pin.
Current channels and the tamper channel have a programmable gain amplifier (PGA) to accommodate low input signals. The PGA
improves the dynamic range of the channel as the input referred noise is reduced when gain increases. The PGA does not introduce any
delay or bandwidth limitation on the current channels compared to the voltage channels. The channels (voltage or current) are always
sampled synchronously. The input impedance of the PGA depends on the programmed gain.
The tamper channel features an input multiplexer to perform both the neutral current measurement and the die temperature measurement.
The tamper channel has a PGA to accommodate low output level current sensors. Programmed gain can be changed when switching
from the tamper to the die temperature sensor source.
2017 Microchip Technology Inc.
DS60001524A-page 11
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H)
4.2
Voltage Reference, Die Temperature Measurement and Calibration Registers
4.2.1
Voltage Reference
ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H) embed an analog voltage reference with a typical output voltage of 1.144V. The temperature drift of the voltage reference can be approximated by a linear fit. For H grade parts, the temperature drift is measured during
manufacturing and stored in the calibration registers (ROM). Two measurements are made: one at a low temperature, TL, and another at
a high temperature, TH. At both temperatures TL and TH, VREF voltage and ADC_TEMP_OUT (ADC I0 reading of the temperature sensor) parameters are saved. From the data obtained, the user can implement a software compensation of the voltage reference.
4.2.2
Die Temperature Sensor
To measure the internal die temperature, ATSENSE-101/ATSENSE-201(H)/ATSENSE-301(H) devices embed a dedicated analog die
temperature sensor that is multiplexed on the tamper channel (ADC I0). By measuring the die temperature periodically and by using the
calibration bits, channel gain drifts over temperature due to the voltage reference can be corrected.
To set the ADC to measure the temperature sensor, the user must set the TEMPMEAS bit in ADC I0 control register and ensure that the
channel gain is set to x1 (0dB).
Once the temperature measurement is selected, the ADC starts to output samples corresponding to the temperature sensor. The first four
samples account for internal digital filters settling and must be ignored. Then, in order to have a repeatable temperature acquisition, the
user must average the ADC output over a minimum of 64 samples. By following this procedure, the temperature acquisition exhibits a
standard deviation of less than 0.25°C in repeatability.
To calculate the real die temperature from the ADC acquisition, the following formula applies:
TJ(°C) = ( (ADC_TEMP_OUT / 2 24) x 1.144 - 0.110) / 0.00049
where ADC_TEMP_OUT is the 24-bit output of ADC I0, averaged over 64 samples. Example: If ADC_TEMP_OUT = 1777345, the
corresponding die temperature is TJ = 22.8°C.
Because the temperature sensor is not offset-calibrated, the absolute temperature reading exhibits a large deviation (typically ±15°C).
4.2.3
Calibration Registers
The registers used in the voltage reference compensation are listed in Table 4-1. The four parameters stored, VREF and
ADC_TEMP_OUT at TL and TH, are:
• REF_TL[11:0] and REF_TH[11:0]
• TEMP_TL[11:0] and TEMP_TH[11:0]
The following rule applies to recover the real values of VREF from the 12-bit coded values in the product registers:
• VREF(TL) = 1.120V + REF_TL[11:0] * 25µV
• VREF(TH) = 1.120V + REF_TH[11:0] * 25µV
Note:
REF_TL[11:0] and REF_TH[11:0] are unsigned 12-bit integers.
The following rule applies to recover the real values of ADC_TEMP_OUT from the 12-bit coded values in the product registers:
• ADC_TEMP_OUT[23:0](TL) = TEMP_TL[11:0]