Datasheet

Data Sheet AD8421
Rev. 0 | Page 3 of 28
SPECIFICATIONS
V
S
= ±15 V, V
REF
= 0 V, T
A
= 25°C, G = 1, R
L
= 2 k, unless otherwise noted.
AR AND BR GRADES
Table 1.
AR Grade BR Grade
Parameter
Test Conditions/
Comments
Min Typ Max Min Typ Max
Unit
COMMON-MODE REJECTION
RATIO (CMRR)
CMRR DC to 60 Hz with 1 kΩ
Source Imbalance
V
CM
= −10 V to +10 V
G = 1 86 94 dB
G = 10 106 114 dB
G = 100 126 134 dB
G = 1000 136 140 dB
Over Temperature, G = 1 T = −40°C to +85°C 80 93 dB
CMRR at 20 kHz V
CM
= −10 V to +10 V
G = 1 80 80 dB
G = 10 90 100 dB
G = 100 100 110 dB
G = 1000 110 120 dB
NOISE
Voltage Noise, 1 kHz
1
V
IN
+, V
IN
− = 0 V
Input Voltage Noise, e
ni
3 3.2 3 3.2 nV/√Hz
Output Voltage Noise, e
no
60 60 nV/√Hz
Peak to Peak, RTI f = 0.1 Hz to 10 Hz
G = 1 2 2 2.2 μV p-p
G = 10 0.5 0.5 μV p-p
G = 100 to 1000 0.07 0.07 0.09 μV p-p
Current Noise
Spectral Density f = 1 kHz 200 200 fA/√Hz
Peak to Peak, RTI f = 0.1 Hz to 10 Hz 18 18 pA p-p
VOLTAGE OFFSET
2
Input Offset Voltage, V
OSI
V
S
= ±5 V to ±15 V 60 25 μV
Over Temperature T
A
= −40°C to +85°C 86 45 μV
Average TC 0.4 0.2 μV/°C
Output Offset Voltage, V
OSO
350 250 μV
Over Temperature T
A
= −40°C to +85°C 0.66 0.45 mV
Average TC 6 5 μV/°C
Offset RTI vs. Supply (PSR) V
S
= ±2.5 V to ±18 V
G = 1 90 120 100 120 dB
G = 10 110 120 120 140 dB
G = 100 124 130 140 150 dB
G = 1000 130 140 140 150 dB
INPUT CURRENT
Input Bias Current 1 2 0.1 0.5 nA
Over Temperature T
A
= −40°C to +85°C 8 6 nA
Average TC 50 50 pA/°C
Input Offset Current 0.5 2 0.1 0.5 nA
Over Temperature T
A
= −40°C to +85°C 2.2 0.8 nA
Average TC 1 1 pA/°C