Data Sheet
SPECIFICATIONS
AD7798/AD7799
AV
DD
= 2.7 V to 5.25 V; DV
DD
= 2.7 V to 5.25 V; GND = 0 V; REFIN(+) = AV
DD
; REFIN(−) = 0 V. All specifications T
MIN
to T
MAX
, unless
otherwise noted.
Table 1.
Parameter
ADC CHANNEL
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
ANALOG INPUTS
Differential Input Voltage Ranges
Absolute AIN Voltage Limits
Unbuffered Mode
Buffered Mode
In-Amp Active
Common-Mode Voltage, V
CM
Analog Input Current
Buffered Mode or In-Amp Active
Average Input Current
AD7798B/AD7799B
4.17 − 470
24
16
Unit
Hz nom
Bits min
Bits min
Test Conditions/Comments
AD7799: f
ADC
< 242 Hz
AD7798
See Table 5 to Table 8
See Table 5 to Table 8
±15
±1
±10
±10
±1
100
±V
REF
/gain
GND − 30 mV
AV
DD
+ 30 mV
GND + 100 mV
AV
DD
– 100 mV
GND + 300 mV
AV
DD
− 1.1
0.5
ppm of FSR max
µV typ
nV/°C typ
µV typ
ppm/°C typ
dB min
V nom
V min
V max
V min
V max
V min
V max
V min
AIN = 1 V/gain, gain ≥ 4
V
REF
= REFIN(+) – REFIN(–), gain = 1 to 128
Gain = 1 or 2
Gain = 1 or 2
Gain = 4 to 128
V
CM
= (AIN(+) + AIN(−))/2, gain = 4 to 128
Average Input Current Drift
Unbuffered Mode
Average Input Current
Average Input Current Drift
Normal Mode Rejection
@ 50 Hz, 60 Hz
@ 50 Hz
@ 60 Hz
Common-Mode Rejection
@ DC
@ 50 Hz, 60 Hz
@ 50 Hz, 60 Hz
±1
±250
±1
±2
±400
±50
65
80
90
100
100
100
nA max
pA max
nA max
pA/°C typ
nA/V typ
pA/V/°C typ
dB min
dB min
dB min
dB min
dB min
dB min
Gain = 1 or 2, update rate < 100 Hz
Gain = 4 to 128, update rate < 100 Hz
AIN3(+)/AIN3(−), 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)
AIN = 1 V/gain, gain ≥ 4
50 ± 1 Hz, 60 ± 1 Hz (FS[3:0] = 1010)
50 ± 1 Hz (FS[3:0] = 1001
), 60 ± 1 Hz
(FS[3:0] = 1000
)
Rev. B | Page 3 of 28
AD [ ANALOG DEVICES ]
