CBM53D04/CBM53D14/CBM53D24
Datasheet
Features
General Description
CBM53D04: 4 buffered 8-Bit DACs in
The
MSOP10L
are quad 8-, 10- and 12-bit buffered voltage
CBM53D14: 4 buffered 10-Bit DACs
output DACs in MSOP10L packages that
operate from a single 2.5V to 5.5V supply,
in MSOP10L
CBM53D04/CBM53D14/CBM53D24
consuming only 500uA at 3V. They have on-
CBM53D24: 4 buffered 12-Bit DACs
chip rail-to-rail output amplifiers with slew
in MSOP10L
rate of 0.7V/us. A 3-wire serial interface
Low power operation: 500uA @ 3V,
600uA @ 5V
2.5V to 5.5V power supply
Power-down to 80nA @ 3V,200nA @ 5V
Double-buffered input logic
Output range:0V to VREF
derived from one reference pin. The outputs
Power-on reset to 0V
of all DACs can be updated simultaneous. It
On-chip, rail-to-rail output buffer
incorporate a power-on reset circuit, and
amplifiers
ensure that the DAC outputs power up to 0V
Temperature range -40℃ to +105℃
and remains there until a valid write takes
compatible
Portable battery-powered instruments
Digital gain and offset adjustment
Programmable voltage and current
standard
SPI,
QSPI,
MICROWIRE, and DSP interface standards is
used, which can operates at clock rates up to
30MHz.
The references for the four DACs are
place to the device. The parts contain a power-
Applications
with
down
feature
that
reduces
the
current
consumption to 200nA @ 5V (80nA @ 3V).
sources
Programmable attenuators
Industrial process controls
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CBM53D04/CBM53D14/CBM53D24
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Functional Block Diagram
Figure 1 Functional Block Diagram
Typical Application Circuit
Figure 2 CBM53D04/CBM53D14/CBM53D24 Typical
Application Circuit
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CBM53D04/CBM53D14/CBM53D24
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Absolute Maximum Ratings
Table 1
TA=25℃,unless otherwise noted.
Parameter1
Sym
Rating
VDD to GND
VDDabs
-0.3V to+7V
Digital Input Voltage to GND
VDigabs
-0.3V to VDD+0.3V
Reference Input Voltage to GND
Vrefabs
-0.3V to VDD+0.3V
VOUTA through VOUTD to GND
Voutabs
-0.3V to VDD+0.3V
TP
-40℃ to +105℃
Operating Temperature Range
Industrial
TS
Storage Temperature Range
Junction TemperatureTJ max
-65℃ to +150℃
TJmax
150℃
Reflow Soldering
Peak Temperature(Pb-free)
260℃
Peak Temperature(non Pb-free)
220℃
Time at Peak Temperature
10 sec to 40 sec
Transient currents of up to 100mA do not cause SCR latch-up.
Recommended Operation Conditions
Table 2
Parameter
Sym
Power supply
Rating
Unit
Min
Max
VDD
2.5
5.5
V
Current dissipation
IDD
400u
600u
A
Ambient Temperature
Ta
-40
105
℃
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Specifications
Table 3
VDD=2.5V to 5.5V; VREF=2V; RL=2KΩ to GND ; CL=200pF to GND; Ta=25℃; unless otherwise
noted.
Parameter
Sym
Test Condition
Min
Typ
Max
Unit
DC Performance1,2
CBM53D04
Resolution
ResN
8
Bits
Relative Accuracy
INL
±0.15
LSB
Differential Nonlinearity
DNL
±0.02
LSB
Monotonic Guaranteed
CBM53D14
Resolution
ResN
10
Bits
Relative Accuracy
INL
±0.5
LSB
Differential Nonlinearity
DNL
±0.05
LSB
Monotonic Guaranteed
CBM53D24
Resolution
ResN
12
Bits
Relative Accuracy
INL
±2
LSB
Differential Nonlinearity
DNL
±0.2
LSB
Offset Error
±0.4
%of FSR
Gain Error
±0.15
%of FSR
20
mV
△VDD=±10%
-60
dB
RL=2KΩ to GND or VDD
200
uV
Lower dead band exists only if
Lower Dead Band
DC Power Supply Rejection
Ratio3
DC Crosstalk3
Monotonic Guaranteed
offset error is negative
PSRR
Reference Input3
VREF Input Range
0.25
VREF Input Impedance
VDD
V
45
KΩ
-80
dB
Minimum Output Voltage4
0
V
Maximum Output Voltage4
VDD
V
DC Output Impedance
0.5
Ω
Reference Feedthrough
Frequency=10KHz
Output Characteristics3
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CBM53D04/CBM53D14/CBM53D24
Datasheet
Short Circuit Current
25
mA
Power-Up Time
5
uS
Logic Input3
Input Low Voltage
VIL
VDD=3V
0.6
V
Input High Voltage
VIH
VDD=3V
2.1
V
pF
3
Pin Capacitance
Power Requirements
Power supply
VDD
IDD (Normal Mode)4
IDD
2.5
5.5
V
VDD=4.5V to 5.5V
VIH=VDD and VIL=GND
600
uA
VDD=2.5V to 3.6V
VIH=VDD and VIL=GND
500
uA
VDD=4.5V to 5.5V
VIH=VDD and VIL=GND
0.2
uA
VDD=2.5V to 3.6V
VIH=VDD and VIL=GND
0.08
uA
IDD (Power-Down Mode)
1 DC specifications tested with the outputs unloaded.
2 Linearity is tested using a reduced code range: CBM53D04 (Code 8 to Code 248); CBM53D14
(Code 28 to Code 995); CBM53D24 (Code 115 to Code 3981).
3 Guaranteed by design and characterization, not production tested.
4 For the amplifier output to reach its minimum voltage, offset error must be negative. For the
amplifier output to reach its maximum voltage, VREF=VDD and offset plus gain error must be
positive.
5 IDD specification is valid for all DAC codes; interface inactive; all DACs active; load
currents excluded.
AC Characteristics
Table 4
VDD=2.5V to 5.5V; VREF=2V; RL=2KΩ to GND ; CL=200pF to GND; Ta=25℃; unless otherwise
noted.
Parameter1
Sym
Test Condition
Min
Typ
Max
Unit
Output Voltage Setting
Time
1/4 scale to 3/4 scale
CBM53D04
change(0x40 to 0xC0)
7
uS
8
uS
9
uS
1/4 scale to 3/4 scale
CBM53D14
change(0x100 to 0x300)
1/4 scale to 3/4 scale
CBM53D24
change(0x400 to 0xC00)
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CBM53D04/CBM53D14/CBM53D24
Datasheet
Slew Rate
0.7
V/uS
40
nV-sec
Digital Feedthrough
1
nV-sec
Digital Crosstalk
1
nV-sec
DAC-to-DAC Crosstalk
3
nV-sec
200
kHz
-70
dB
Major-Code Transition
1 LSB change around major
Glitch Energy
carry
Multiplying Bandwidth
VREF=2V±0.1VP-P
VREF=2.5V±0.1VP-P;
Total Harmonic Distortion
Frequency=10KHz
1 Guaranteed by design and characterization, not production tested.
Timing Characteristics
VDD = 2.5V to 5.5V; all specifications TMIN to TMAX, unless otherwise noted.
Parameter1,2,3
Limit at TMIN, TMAX
Unit
Test
Conditions/Comments
VDD=2.5V to 3.6V
VDD=3.6V to 5.5V
t1
40
33
ns min
SCLK cycle time
t2
16
13
ns min
SCLK high time
t3
16
13
ns min
SCLK low time
t4
16
13
ns min
t5
5
5
ns min
Data setup time
t6
4.5
4.5
ns min
Data hold time
t7
0
0
ns min
t8
80
33
ns min
SYNC to SCLK falling
edge setup time
SCLK falling edge to
SYNC rising edge
Minimum SYNC high
time
1
Guaranteed by design and characterization, not production tested.
2
All input signals are specified with tr = tf = 5ns (10% to 90% of VDD) and timed from a voltage
level of (VIL + VIH)/2.
3
See Figure 3.
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CBM53D04/CBM53D14/CBM53D24
Datasheet
Figure 3. Serial Interface Timing Diagram
Pin Configurations
Figure 4. MSOP10L Pin Configuration
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CBM53D04/CBM53D14/CBM53D24
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Pin Function Descriptions
Table 5
Pin Name
Pin No.
Function
VDD
1
Power
VOUTA
2
O
VOUTB
3
O
VOUTC
4
O
Refin
5
I
VOUTD
6
O
GND
7
Ground
Description
Power Supply Input. These parts can be operated from 2.5V
to 5.5V and the supply can be decoupled to GND.
Buffered Analog Output Voltage from DAC A. The output
amplifier has rail-to-rail operation.
Buffered Analog Output Voltage from DAC B. The output
amplifier has rail-to-rail operation.
Buffered Analog Output Voltage from DAC C. The output
amplifier has rail-to-rail operation.
Reference Input Pin for All Four DACs. It has an input range
from 0.25V to VDD.
Buffered Analog Output Voltage from DAC D. The output
amplifier has rail-to-rail operation.
Ground Reference Point for All Circuitry on the Part.
Serial Data Input.
Din
8
I
This device has a 16-bit shift register. Data is clocked into
the register on the falling edge of the serial clock input. The
Din input buffer is powered down after each write cycle.
Serial Clock Input.
Data is clocked into the input shift register on the falling
Sclk
9
I
edge of the serial clock input. Data can be transferred at
clock speeds up to 30MHz. The Sclk input buffer is
powered down after each write cycle.
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Active Low Control Input.
This is the frame synchronization signal for the input data.
When goes low, it enables the input shift register and data
is transferred in on the falling edges of the following
Sync
10
I
16clocks.
If SYNC is taken high before the 16th falling edge of Sclk,
the rising edge of SYNC acts as an interrupt and the write
sequence is ignored by the device.
I:Input, O:Output
Typical Performance Characteristic
Figure 5. CBM53D14 Typical INL Plot
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Figure 6. CBM53D24 Typical INL Plot
Figure 7. CBM53D14 Typical DNL Plot
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Figure 8. CBM53D24 Typical DNL Plot
Figure 9. Vout Source and Sink Current Capability
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Figure 10. Half-scale setting (0.25 to 0.75 Scale Code Change)
Figure 11. Exiting Power-down to Midscale
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Functional Description
The CBM53D04/CBM53D14/CBM53D24 are quad, resistor-string DACs fabricated on a CMOS
process with resolutions of 8, 10 and 12 bits, respectively. Each contains four output buffer
amplifiers and is written to via a 3-wire serial interface. They operate from single supplies of
2.5V to 5.5V, and the output buffer amplifiers provide rail-to-rail output swing with a slew rate
of 0.7 V/us. The four DACs share a single reference input pin. The devices have programmable
power-down modes, in which all DACs can be turned off completely with a high impedance
output.
The architecture of one DAC channel consists of a resistor-string DAC followed by an output
buffer amplifier. The voltage at the Refin pin provides the reference voltage for the DAC. The
input coding to the DAC is straight binary, the ideal output voltage is given by
VOUT = VREF
×D
… … … … … … … … … …Formula 1
2N
Where D=decimal equivalent of the binary code that is loaded to the DAC register:
0–255 for CBM53D04 (8 bits)
0—1023 for CBM53D14(10 bits)
0—4095 for CBM53D24(12bits)
N=DAC resolution.
There is a single reference input pin for the four DACs. The reference input is not buffered. The
user can have a reference voltage as low as 0.25V or as high as VDD because there is no restriction
due to the headroom or footroom requirements of any reference amplifier. It is recommended to
use a buffered reference in the external circuit. The input impedance is typical 45kΩ.
The output buffer amplifier is capable of generating rail-to-rail voltages on its output, giving an
output range of 0V to VDD when the reference is VDD. It is capable of driving a load of 2kΩ to GND
or VDD , in parallel with 500pF to GND or VDD. The slew rate is 0.7V/us with a half-scale settling
time to ±0.5LSB(at 12 bits) of 8us.
The CBM54D04/CBM53D14/CBM53D24 are provided with a power-on reset function, so that
they power up in a defined state. The power-on state uses normal operation and an output
voltage set to 0V. Both input and DAC registers are filled with zeros and remain so until a valid
write sequence is made to the device.
The CBM54D04/CBM53D14/CBM53D24 are controlled over a versatile, 3-wire serial interface
that operates at clock rates up to 30MHz and are compatible with SPI,QSPI,MICROWIRE, and
DSP interface standards.
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The 3-wire serial interface
(a). CBM53D04 Input Shift Register Contents
(b). CBM53D14 Input Shift Register Contents
(c). CBM53D24 Input Shift Register Contents
Figure42. CBM53D04/CBM53D14/CBM53D24 Input Shift Register Contents
Input Shift Register
The input shift register is 16 bits wide. Data is loaded into the device as a 16-bit word under the
control of a serial clock input, Sclk. The 16-bit word consists of four control bits followed by 10
or 12 bits of DAC data, depending on the device type. Data is loaded MSB first (Bit15) and the
first two bits determine whether the data is for DAC A ,DAC B ,DAC C, or DAC D. Bit 13 and Bit
12 control the operating mode of the DAC. Bit 13 is PD, and determines whether the part is in
normal or power-down mode. Bit 12 is LDAC, and controls when DAC registers and outputs are
updated.
Table 6 Address Bits
A1
A0
DAC Addressed
0
0
DAC A
0
1
DAC B
1
0
DAC C
1
1
DAC D
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Address and Control Bits
PD:
0: All four DACs go into power-down mode, consuming only 200nA @ 5V. The DAC
outputs enter a high impedance state.
1: Normal operation.
LDAC 0: All four DAC registers and, therefore, all DAC outputs updated simultaneously on
completion of the write sequence.
1: Only addressed input register is updated. There is no change in the content of the DAC
registers.
The CBM53D24 uses all 12 bits of DAC data; the CBM53D14 uses 10 bits and ignores the 2 LSB
Bits. The CBM53D04 uses 8 bits and ignores the last four bits. The data format is straight binary,
with all 0s corresponding to 0V output and all 1s corresponding to full-scale output (VREF-1LSB).
The Sync input is a level-triggered input that acts as a frame synchronization signal and chip
enable. Data can be transferred into the device only while Sync is low. To start the serial data
transfer, take Sync low. After Sync goes low, serial data shifts into the device's input shift
register on the falling edges of Sclk for 16 clock pulses. Any data and clock pulses after the 16th
falling edge of Sclk are ignored because the Sclk and Din input buffers are powered down. No
further serial data transfer occurs until Sync is taken high and low again. Sync can be taken
high after the falling edge of the 16th Sclk pulse.
After the end of the serial data transfer, data automatically transfers from the input shift
register to the input register of the selected DAC. If Sync is taken high before the 16th falling
edge of Sclk, the data transfer is aborted and the DAC input registers are not updated.
When data has been transferred into three of the DAC input registers, all DAC registers and all
DAC outputs are simultaneously updated by setting LDAC low when writing to the remaining
DAC input register.
Low Power Serial Interface
To reduce the power consumption of the device even further, the interface fully powers up only
when the device is being written to, that is , on the falling edge of Sync. As soon as the 16-bit
control word has been written to the part, the Sclk and Din input buffers are powered down.
They power up again only following a falling edge of Sync.
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Double-Buffered Interface
The CBM53D04/CBM53D14/CBM53D24 DACs have double-buffered interfaces consisting of two
banks of registers-input registers and DAC registers. The input register is directly connected to
the input shift register and the digital code is transferred to the relevant input register on
completion of a valid write sequence. The DAC register contains the digital code used by the
resistor string.
Access to the DAC register is controlled by the LDAC bit. When the LDAC bit is set high, the
DAC register is latched and hence the input register can change state without affecting the
contents of the DAC register. However, when the LDAC bit is set low, all DAC registers are
update after a complete write sequence.
This is useful if the user requires simultaneous updating of all DAC outputs. The user can write
to three of the input registers individually and then, by setting the LDAC bit low when writing to
the remaining DAC input register, all outputs update simultaneously.
These parts contain an extra feature whereby the DAC register is not updated unless its input
register has been update since the last time that LDAC was brought low. Normally, when LDAC
is brought low, the DAC registers are filled with the contents of the input register. In the case of
the CBM53D04/CBM53D14/CBM53D24 the part updates the DAC register only if the input
register has been changed since the last time the DAC register was updated, thereby removing
unnecessary digital crosstalk.
Power-Down Mode
The CBM53D04/CBM53D14/CBM53D24 have low power consumption, dissipation only 1.5mW
with a 3V supply and 3mW with a 5V supply. Power consumption can be further reduced when
the DACs are not in use by putting them into power-down mode, selected by a 0 on Bit 13 (PD)
of the control word.
When the PD bit is set to 1, all DACs work normally with a typical power consumption of 600uA
at 5V (500uA at 3V ). However, in power-down mode, the supply current falls to 200nA at 5V
(80nA at 3V) when all DACs are powered down. Not only does the supply current drop, but also
the output stage is internally switched from the output of the amplifier, making it open-circuit.
This has the advantage that the output is three-stated while the part is in power-down mode,
and provides a defined input condition for whatever is connected to the output of the DAC
amplifier.
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CBM53D04/CBM53D14/CBM53D24
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The bias generator, the output amplifier, the resistor string, and all other associated linear
circuitry are shut down when the power-down mode is activated. However, the contents of the
registers are unaffected when in power-down. The time to exit power-down is typically 5us. This
is the time from the falling edge of the 16th Sclk pulse to when the output voltage deviates from
its power down voltage.
Typical Application Circuit
The CBM53D04/CBM53D14/CBM53D24 can be used with a wide range of reference voltages
where the devices offer full, one-quadrant multiplying capability over a reference range of 0V to
VDD. More typically, these devices are used with a fixed, precision reference voltage.
If an output range of 0V to VDD is required, the simplest solution is to connect the reference
input to VDD. As this supply is not very accurate and can be noisy, the
CBM53D04/CBM53D14/CBM53D24 can be powered from the reference voltage; for example,
using a 5V reference. The current required is 600uA supply current and approximately 112uA
into the reference input. This is with no load on the DAC outputs. When the DAC outputs are
loaded, the reference also needs to supply the current to the loads.
Decoding Multiple CBM53D04/CBM53D14/CBM53D24
The SYNC pin on the CBM53D04/CBM53D14/CBM53D24 can be used in applications to decode
a number of DACs. In this application, all the DACs in the system receive the same serial clock
and serial data, but SYNC can only be active to one of the devices at any one time, allowing
access to only one DAC in this system. The 74HC139 can be used as a 2-to-4-line decoder to
address any of the DACs in the system. To prevent timing errors, the enable input must be
brought to its inactive state while the coded address inputs are changing state.
Power Supply Bypassing and Grounding
In any circuit where accuracy is important, careful consideration of the power supply and
ground return layout helps to ensure the rated performance. The printed circuit board on which
the CBM53D04/CBM53D14/CBM53D24 is mounted is designed so that the analog and digital
sections are separated and confined to certain areas of the board. If the
CBM53D04/CBM53D14/CBM53D24 are in a system where multiple devices require an AGNDto-DGND connection, the connection is made at one point only. The star ground point is
established as close as possible to the device.
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CBM53D04/CBM53D14/CBM53D24
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The CBM53D04/CBM53D14/CBM53D24 has ample supply bypassing of 10uF in parallel with
0.1uF on the supply located as close to the package as possible, ideally right up against the
device. The 10uF capacitors are the tantalum bead type. The 0.1uF capacitor has low effective
series resistance (ESR) and effective series inductance (ESI).
The power supply lines of the CBM53D04/CBM53D14/CBM53D24 use as large a trace as
possible to provide low impedance paths and reduce the effects of glitches on the power
supply line. Fast switching signals such as clocks are shielded with digital ground to avoid
radiating noise to other parts of the board, and are never run near the reference inputs .Avoid
crossover of digital and analog signals. Traces on opposite sides of the board run at right angles
to each other. This reduces the effects of feedthrough through the board.
Outline Dimensions
SYBMOL
MILLIMETER
MIN
NOM
MAX
A
-
-
1.10
A1
0.05
-
0.15
A2
0.75
0.85
0.95
A3
0.30
0.35
0.40
b
0.19
-
0.28
b1
0.18
0.20
0.23
c
0.15
-
0.20
c1
0.14
0.152
0.16
D
2.90
3.00
3.10
E
4.70
4.90
5.10
E1
2.90
3.00
3.10
e
L
0.50 BSC
0.40
L1
θ
L/F 载体尺寸
(mil)
Figure 5 MSOP10L Dimensions shown in millimeters
-
0.70
0.95 BSC
0
-
8°
71×96
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