AD7785 Analog Devices, AD7785 Datasheet - Page 3

• Manufacturer Part Number: AD7785
• Description: 3-Channel, Low Noise, Low Power, 20-Bit ?-? ADC with On-Chip In-Amp and Reference
• Manufacturer: Analog Devices

Specifications of AD7785

• Resolution (bits): 20bit
• # Chan: 3
• Sample Rate: n/a
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni
• Ain Range: ± (Vref/Gain)
• Adc Architecture: Sigma-Delta
• Pkg Type: SOP

SPECIFICATIONS
AV
Table 1.
Parameter
ADC CHANNEL
ANALOG INPUTS
Output Update Rate
No Missing Codes
Resolution
Output Noise and Update Rates
Integral Nonlinearity
Offset Error
Offset Error Drift vs. Temperature
Full-Scale Error
Gain Drift vs. Temperature
Power Supply Rejection
Differential Input Voltage Ranges
Absolute AIN Voltage Limits
Analog Input Current
Normal Mode Rejection
Common-Mode Rejection
DD
Buffered Mode
In-Amp Active
Common-Mode Voltage, V
@ DC
@ 50 Hz, 60 Hz
@ 50 Hz, 60 Hz
Unbuffered Mode
Buffered Mode or In-Amp Active
Unbuffered Mode
Internal Clock
External Clock
= 2.7 V to 5.25 V; DV
Average Input Current
Average Input Current Drift
Average Input Current
Average Input Current Drift
@ 50 Hz, 60 Hz
@ 50 Hz
@ 60 Hz
@ 50 Hz, 60 Hz
@ 50 Hz
@ 60 Hz
3
3, 5
2
2
2
2
DD
4
2
2
= 2.7 V to 5.25 V; GND = 0 V; all specifications T
CM
4
AD7785B
4.17 to 470
20
±15
±1
±10
±10
±1
±3
100
±V
GND – 30 mV
AV
GND + 100 mV
AV
GND + 300 mV
AV
0.5
±1
±250
±2
±400
±50
65
80
90
80
94
90
100
100
100
DD
DD
DD
REF
/Gain
+ 30 mV
– 100 mV
– 1.1
1
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Unit
Bits min
μV typ
nV/°C typ
μV typ
ppm/°C typ
ppm/°C typ
dB min
V min
V max
V min
V max
V min
V max
V min
nA max
pA max
pA/°C typ
nA/V typ
pA/V/°C typ
dB min
dB min
dB min
dB min
dB min
dB min
dB min
dB min
dB min
Hz nom
ppm of FSR max
V nom
MIN
to T
MAX
, unless otherwise noted.
Test Conditions/Comments
See Output Noise and Resolution Specifications
See Output Noise and Resolution Specifications
Gain = 1 to 16, external reference
Gain = 32 to 128, external reference
AIN = 1 V/gain, gain ≥ 4, external reference
V
gain = 1 to 128
Gain = 1 or 2
Gain = 1 or 2
Gain = 4 to 128
V
Gain = 1 or 2, update rate < 100 Hz
Gain = 4 to 128, update rate < 100 Hz
Gain = 1 or 2
Input current varies with input voltage
80 dB typ, 50 ± 1 Hz, 60 ± 1 Hz, FS[3:0] = 1010
90 dB typ, 50 ± 1 Hz, FS[3:0] = 1001
100 dB typ, 60 ± 1 Hz, FS[3:0] = 1000
90 dB typ, 50 ± 1 Hz, 60 ± 1 Hz, FS[3:0] = 1010
100 dB typ, 50 ± 1 Hz, FS[3:0] = 1001
100 dB typ, 60 ± 1 Hz, FS[3:0] = 1000
AIN = 1 V/gain, gain ≥ 4
50 ± 1 Hz, 60 ± 1 Hz, FS[3:0] = 1010
50 ± 1 Hz (FS[3:0] = 1001)
(FS[3:0] = 1000)
REF
CM
= (AIN(+) + AIN(−))/2, gain = 4 to 128
= REFIN(+) − REFIN(−) or internal reference,
6
6
, 60 ± 1 Hz
6
6
AD7785
6
6
6
6
6