Datasheet

Data Sheet AD8421
Rev. 0 | Page 5 of 28
AR Grade BR Grade
Parameter
Test Conditions/
Comments
Min Typ Max Min Typ Max
Unit
POWER SUPPLY
Operating Range Dual supply ±2.5 ±18 ±2.5 ±18 V
Single supply 5 36 5 36 V
Quiescent Current 2 2.3 2 2.3 mA
Over Temperature T
A
= −40°C to +85°C 2.6 2.6 mA
TEMPERATURE RANGE
For Specified Performance −40 +85 −40 +85 °C
Operational
5
−40 +125 −40 +125 °C
1
Total voltage noise = √(e
ni
2
+ (e
no
/G)
2
+ e
RG
2
). See the Th section for more information. eory of Operation
2
Total RTI V
OS
= (V
OSI
) + (V
OSO
/G).
3
These specifications do not include the tolerance of the external gain setting resistor, R
G
. For G > 1, add R
G
errors to the specifications given in this table.
4
Input voltage range of the AD8421 input stage only. The input range can depend on the common-mode voltage, differential voltage, gain, and reference voltage.
See the section for more details. Input Voltage Range
5
See the section for expected operation between 85°C and 125°C. Typical Performance Characteristics
ARM AND BRM GRADES
Table 2.
ARM Grade BRM 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 84 92 dB
G = 10 104 112 dB
G = 100 124 132 dB
G = 1000 134 140 dB
Over Temperature, G = 1 T
A
= −40°C to +85°C 80 90 dB
CMRR at 20 kHz V
CM
= −10 V to +10 V
G = 1 80 80 dB
G = 10 90 90 dB
G = 100 100 100 dB
G = 1000 100 100 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 70 50 μV
Over Temperature T
A
= −40°C to +85°C 135 135 μV
Average TC 0.9 0.9 μV/°C
Output Offset Voltage, V
OSO
600 400 μV
Over Temperature T
A
= −40°C to +85°C 1 1 mV
Average TC 9 9 μV/°C