Data Sheet AD8218
Rev. B | Page 3 of 16
SPECIFICATIONS
T
OPR
= −40°C to +125°C, T
A
= 25°C, R
L
= 25 kΩ (R
L
is the output load resistor), input common-mode voltage (V
CM
) = 4 V, unless
otherwise noted.
Table 1.
Parameter Min Typ Max Unit Test Conditions/Comments
GAIN
Initial 20 V/V
Accuracy ±0.1 % V
O
≥ 0.1 V dc, T
A
Accuracy over Temperature ±0.35 % T
OPR
Gain vs. Temperature ±5 ppm/°C T
OPR
Offset Voltage (RTI
1
) ±200 µV 25°C
Over Temperature (RTI
1
) ±300 µV T
OPR
Offset Drift ±100 nV/°C T
OPR
Bias Current
2
130 µA T
A
, input common mode = 4 V, V
S
= 4 V
220 µA T
OPR
, input common mode = 4 V, V
S
= 4 V
Common-Mode Input Voltage Range 4 80 V Common-mode continuous
Differential Input Voltage Range
3
0 250 mV Differential input voltage
Common-Mode Rejection (CMRR) 90 110 dB T
OPR
OUTPUT
Output Voltage Range Low 0.01 V
Output Voltage Range High V
S
− 0.1 V T
A
INTERNAL REFERENCE (ENB PIN CONNECTED TO GND)
Initial Value 80 mV
Voltage at OUT with a differential input of
0 V and a common-mode input of 4 V
Offset (RTI
1
) −150 +150 µV
Offset Drift (RTO
4
) ±10 µV/°C
S
S
REFERENCE INPUT (REF, PIN 7)
Input Impedance 1.5 MΩ
Input Current 3 60 µA
REF
Input Voltage Range 0 5 V
Input-to-Output Gain 1 ± 0.0001 V/V
DYNAMIC RESPONSE
Small-Signal −3 dB Bandwidth 450 kHz
Slew Rate 1 V/µs
NOISE
0.1 Hz to 10 Hz (RTI
1
) 2.3 µV p-p
Spectral Density, 1 kHz (RTI
1
) 110 nV/√Hz
POWER SUPPLY
Operating Range (Pin 2 Floating) 4 80 V
Power regulated from common mode,
V
S
pin floating
V
S
Range (Pin 2) 4 5.5 V
V
S
must be less than 5.5 V if standalone
supply is used
Quiescent Current over Temperature
Throughout input common mode
Power Supply Rejection Ratio (PSRR) 90 110 dB
OPR
TEMPERATURE RANGE
For Specified Performance −40 +125 °C
1
RTI = referred to input.
2
Refer to Figure 9 for more information on the input bias current. This current varies based on the input common-mode voltage. The input bias current flowing to the
+IN pin is also the supply current to the internal LDO.
3
The differential input voltage is specified as 250 mV because the output is internally clamped to 5.2 V. This ensures that the output voltage does not exceed the typical
ADC input range, preventing damage. The AD8218 can survive up to ±5 V differentially but will only amplify ~250 mV correctly due to the output clamping function.
4
RTO = referred to output.
