Data Sheet AD7790
Rev. A | Page 3 of 20
AD7790—SPECIFICATIONS
1
Table 1. (V
DD
= 2.5 V to 5.25 V; REFIN(+) = 2.5 V; REFIN(–) = GND; CDIV1 = CDIV0 = 0; GND = 0 V;
all specifications T
MIN
to T
MAX
, unless otherwise noted.)
Parameter AD7790B Unit Test Conditions/Comments
ADC CHANNEL SPECIFICATION
Output Update Rate 9.5 Hz min nom
120 Hz max nom
ADC CHANNEL
No Missing Codes
2
16 Bits min
±V
REF
Range, Update Rate
20 Hz
Resolution 16 Bits p-p 9.5 Hz Update Rate
Output Noise 1.1 µV rms typ
Integral Nonlinearity ±15 ppm of FSR max 3.5 ppm typ
Offset Error ±3 µV typ
Offset Error Drift vs. Temperature ±10 nV/°C typ
Full-Scale Error
3
±10 µV typ
Gain Drift vs. Temperature ±0.5 ppm/°C typ
Power Supply Rejection 90 dB min Input Range = ±REFIN, 100 dB typ
ANALOG INPUTS
Differential Input Voltage Ranges ±REFIN/GAIN V nom REFIN = REFIN(+) – REFIN(–); GAIN = 1, 2, 4, or 8
Absolute AIN Voltage Limits
2
GND + 100 mV V min Buffered Mode of Operation
V
DD
– 100 mV V max
Analog Input Current Buffered Mode of Operation
2
Average Input Current Drift ±5 pA/°C typ
Absolute AIN Voltage Limits
2
GND – 30 mV V min Unbuffered Mode of Operation
V
DD
+ 30 mV V max
Analog Input Current
Unbuffered Mode of Operation
Input current varies with input voltage.
Average Input Current ±400 nA/V typ
Average Input Current Drift ±50 pA/V/°C typ
Normal Mode Rejection
2
@ 50 Hz, 60 Hz 65 dB min 73 dB typ, 50 ± 1 Hz, 60 ± 1 Hz, FS[2:0] = 100
4
@ 50 Hz 80 dB min 90 dB typ, 50 ± 1 Hz, FS[2:0] = 101
4
90 dB typ, 60 ± 1 Hz, FS[2:0] = 011
4
Common Mode Rejection Input Range = ±REFIN, AIN = 1 V
@ DC 90 dB min 100 dB typ (FS[2:0] = 100
4
)
@ 50 Hz, 60 Hz
2
100 dB min 50 ± 1 Hz (FS[2:0] = 101
4
), 60 ± 1 Hz (FS[2:0] = 011
4
)
REFERENCE INPUT REFIN = REFIN(+) – REFIN(–)
REFIN Voltage 2.5 V nom
Reference Voltage Range
2
0.1 V min
V
DD
V max
Absolute REFIN Voltage Limits
2
V
DD
+ 30 mV V max
Average Reference Input Current 0.5 µA/V typ
Average Reference Input Current Drift ±0.03 nA/V/°C typ
1
Temperature Range –40°C to +105°C.
2
Specification is not production tested, but is supported by characterization data at initial product release.
3
Full-scale error applies to both positive and negative full-scale and applies at the factory calibration conditions (V
DD
= 4 V).
4
FS[2:0] are the three bits used in the filter register to select the output word rate.