Datasheet AD8421-KGD (Analog Devices)

3 nV/√Hz, Low Power Instrumentation Amplifier Known Good Die AD8421-KGD FEATURES FUNCTIONAL BLOCK DIAGRAM Low power: 2.3 mA maximum quiescent current Low noise –IN +VS 3.2 nV/√Hz maximum input voltage noise at 1 kHz RG VOUT 200 fA/√Hz typical current noise spectral density at 1 kHz RG REF Excellent ac specifications +IN –VS 10 MHz typical small signal bandwidth (gain = 1 and gain = 10) AD8421-KGD
001
2 MHz typical small signal bandwidth (gain = 100)
20316-
0.6 µs typical settling time to 0.001% (gain = 10)
Figure 1.
80 dB minimum CMRR at 20 kHz (gain = 1) 35 V/µs typical slew rate High precision dc performance 84 dB minimum CMRR DC to 60 Hz with 1 kΩ source imbalance (gain = 1) 0.9 µV/°C maximum input offset voltage, average temperature coefficient
The 10 MHz small signal bandwidth, 35 V/µs slew rate, and
5 ppm/°C maximum gain vs. temperature (gain = 1)
0.6 µs settling time to 0.001% (gain = 10) al ow the AD8421-KGD
2 nA maximum input bias current
to amplify high speed signals and excel in applications that require
Inputs protected to 40 V from opposite supply ±2.5 V to ±18 V dual supply (+5 V to +36 V single supply)
high channel count, multiplexed systems. Even at higher gains,
Gain set with a single resistor (gain = 1 to 10,000)
the current feedback architecture maintains high performance.
Known Good Die (KGD): these die are fully guaranteed to
For example, at gain = 100, the bandwidth is 2 MHz and the
data sheet specification.
settling time is 0.8 µs.
APPLICATIONS
The AD8421-KGD has excel ent distortion performance, making this device suitable for use in demanding applications such as
Medical instrumentation
vibration analysis.
Precision data acquisition Microphone preamplification
The AD8421-KGD delivers 3 nV/√Hz input voltage noise and
Vibration analysis
200 fA/√Hz current noise spectral density with only 2 mA
Multiplexed input applications
quiescent current, making the device an ideal choice for
ADC driver
measuring low level signals. For applications with high source
GENERAL DESCRIPTION
impedance, the AD8421-KGD employs innovative process technology and design techniques to provide noise performance The AD8421-KGD is a low cost, low power, low noise, ultralow that is limited only by the sensor. bias current, high speed instrumentation amplifier that is ideal y suited for a broad spectrum of signal conditioning and data The AD8421-KGD uses unique protection methods to ensure acquisition applications. This device features high CMRR, robust inputs while still maintaining low noise. This protection allowing the device to extract low level signals in the presence of allows input voltages up to 40 V from the opposite supply rail high frequency common-mode noise over a wide temperature without damage to the device. range. A single resistor sets the gain from 1 to 10,000. The reference pin can be used to apply a precise offset to the output voltage. The AD8421-KGD is specified from −40°C to +85°C and operational to 125°C. Additional application and technical information can be found in the AD8421 data sheet.
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Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS OUTLINE DIMENSIONS DIE SPECIFICATIONS AND ASSEMBLY RECOMMENDATIONS ORDERING GUIDE