1 Features
1• Low offset voltage: 10 μV (typ), 35 μV (max)
• Gain drift: 5 ppm/°C (G = 1),
35 ppm/°C (G > 1) (max)
• Noise: 7 nV/√Hz
• Bandwidth: 4.7 MHz (G = 1), 290 kHz (G = 100)
• Stable with 1-nF capacitive loads
• Inputs protected up to ±40 V
• Common-mode rejection: 112 dB, G = 10 (min)
• Power supply rejection: 110 dB, G = 1 (min)
• Supply current: 650 μA (max)
• Supply range:
– Single-supply: 4.5 V to 36 V
– Dual-supply: ±2.25 V to ±18 V
• Specified temperature range: –40°C to +125°C
• Packages: 8-pin SOIC, VSSOP, and WSON

2 Applications
• Analog input module
• Flow transmitter
• Battery test
• LCD test
• Electrocardiogram (ECG)
• Surgical equipment
• Process analytics (pH, gas, concentration, force
and humidity)

3 Description
The INA821 is a high-precision instrumentation
amplifier that offers low power consumption and
operates over a wide single-supply or dual-supply
range. A single external resistor sets any gain from 1
to 10,000. The device has high precision as a result
of super-beta input transistors, which provide low
input offset voltage, offset voltage drift, input bias
current, and input voltage and current noise.
Additional circuitry protects the inputs against
overvoltage up to ±40 V.
The INA821 is optimized to provide a high commonmode
rejection ratio. At G = 1, the common-mode
rejection ratio exceeds 92 dB across the full input
common-mode range. The device is designed for lowvoltage
operation from a 4.5-V single supply, and
dual supplies up to ±18 V.
The INA821 is available in 8-pin SOIC, VSSOP, and
WSON packages, and is specified over the –40°C to
+125°C temperature range.