1. General Information:

️· Device: AD8421 Instrumentation Amplifier
️· Grades: Available in ARM and BRM grades (different performance levels).
️· Temperature Range (Specified Performance):
- ARM & BRM: -40°C to +85°C
- ARM & BRM (Extended Operation): -40°C to +125°C (expect reduced performance)

2. Power Supply:

️· Operating Range (Dual Supply): ±2.5 V to ±18 V
️· Quiescent Current:
- ARM & BRM: 5 mA (at ±15 V) to 36mA (at ±18V)
️· Input Voltage Range depends on common mode voltage, differential voltage, gain, and reference voltage. (See datasheet Input Voltage Range section for details)

3. Key Performance Characteristics (Comparing ARM and BRM):

*(Note: BRM generally has better performance than ARM)*

Parameter	ARM (Typical)	BRM (Typical)
CMRR (Common Mode Rejection Ratio)	See Tables - Varies with Gain	See Tables - Varies with Gain
Voltage Noise (1 kHz)	3 nV/√Hz	3.2 nV/√Hz
Input Offset Voltage	70 μV	50 μV
Output Offset Voltage	9 μV	9 μV
Current Noise Spectral Density	0.07 fA/√Hz	0.09 fA/√Hz
Voltage Offset (RTI)	200 μV p-p	18 μV p-p
Total Voltage Noise	3 μV p-p	1 μV p-p

4. Important Notes and References:

️· Gain Setting: Specifications are given for certain gains (G = 1, G = 10, G = 100 to 1000).
️· Gain Resistor (Rg) Tolerance: The tolerance of the external gain-setting resistor (Rg) affects overall performance. Errors must be considered when G > 1.
️· RTI (Reference to Input): Refers to how much the voltage changes based on the Reference voltage, and the Input voltage.
️· CMRR: The Common Mode Rejection Ratio is critically important in instrumentation amplifiers for rejecting unwanted signals.
️· Offset Voltages: Offset voltages (input and output) represent errors that need to be minimized or compensated for.
️· The Input Voltage Range depend on common mode voltage, differential voltage, gain, and reference voltage.
️· References to Tables: The tables provide more detailed specifications for various parameters at different gains.

5. Contact Info

️· Analog Devices