GENERAL DESCRIPTION
The AD8421is a low cost, low power, extremely low noise, ultra low bias current, high speed instrumentation amplifier that is ideally suited for a broad spectrum of signal conditioning and data acquisition applications. This product features extremely high CMRR, allowing it to extract low level signals in the presence of high frequency common-mode noise over a wide temperature
range. The 10 MHz bandwidth, 35 V/μs slew rate, and 0.6 μs settling time to 0.001% (G = 10) allow the AD8421to amplify high speed signals and excel in applications that require high channel count, multiplexed systems. Even at higher gains, the current feedback architecture maintains high performance; for example, at G = 100, the bandwidth is 2 MHz and the settling time is 0.8 μs. The
AD8421has excellent distortion performance, making it suitable for use in demanding applications such as vibration analysis.

FEATURES
Low power
2.3 mA maximum supply current
Low noise
3.2 nV/√Hz maximum input voltage noise at 1 kHz
200 fA/√Hz current noise at 1 kHz
Excellent ac specifications
10 MHz bandwidth (G = 1)
2 MHz bandwidth (G = 100)
0.6 μs settling time to 0.001% (G = 10)
80 dB CMRR at 20 kHz (G = 1)
35 V/μs slew rate
High precision dc performance (AD8421BRZ)
94 dB CMRR minimum (G = 1)
0.2 μV/°C maximum input offset voltage drift
1 ppm/°C maximum gain drift (G = 1)
500 pA maximum input bias current
Inputs protected to 40 V from opposite supply
±2.5 V to ±18 V dual supply (5 V to 36 V single supply)
Gain set with a single resistor (G = 1 to 10,000)

APPLICATIONS
Medical instrumentation
Precision data acquisition
Microphone preamplification
Vibration analysis
Multiplexed input applications
ADC driver

SPECIFICATIONS
VS= ±15 V, VREF= 0 V, TA= 25°C, G = 1, RL= 2 kΩ, unless otherwise noted.