ADI AD8422ARZ-R7

The AD8422 is a high precision, low power, low noise, rail-to-rail instrumentation amplifier that delivers the best performance per unit microampere in the industry. The AD8422 processes signals with ultralow distortion performance that is load independent over its full output range. The AD8422 is the third generation development of the industrystandard AD620. The AD8422 employs new process technologies and design techniques to achieve higher dynamic range and lower errors than its predecessors, while consuming less than one-third of the power. The AD8422 uses the high performance pinout introduced by the AD8221. Very low bias current makes the AD8422 error-free with high source impedance, allowing multiple sensors to be multiplexed to the inputs. Low voltage noise and low current noise make the AD8422 an ideal choice for measuring a Wheatstone bridge. The wide input range and rail-to-rail output of the AD8422 bring all of the benefits of a high performance in-amp to singlesupply applications. Whether using high or low supply voltages, the power savings make the AD8422 an excellent choice for high channel count or power sensitive applications on a very tight error budget. The AD8422 uses robust input protection that ensures reliability without sacrificing noise performance. The AD8422 has high ESD immunity, and the inputs are protected from continuous voltages up to 40 V from the opposite supply rail. A single resistor sets the gain from 1 to 1000. The reference pin can be used to apply a precise offset to the output voltage. The AD8422 is specified from -40°C to +85°C and has typical performance curves to 125°C. It is available in 8-lead MSOP and 8-lead SOIC packages.

• Low power: 330 μA maximum quiescent current
• Rail-to-rail output
• Low noise and distortion 8 nV/√Hz maximum input voltage noise at 1 kHz 0.15 μV p-p RTI noise (G = 100) 0.5 ppm nonlinearity with 2 kΩ load (G = 7)
• Excellent ac specifications 80 dB minimum CMRR at 10 kHz (G = 1) 2.2 MHz bandwidth (G = 7)
• High precision dc performance (AD8422BRZ) 150 dB minimum CMRR (G = 1000) 0.04% maximum gain error (G = 1000) 0.3 μV/°C maximum input offset drift 0.5 nA maximum input bias current
• Wide supply range 4.6 V to 36 V single supply ±2.3 V to ±18 V dual supply
• Input overvoltage protection: 40 V from opposite supply
• Gain range: 1 to 1000

• Medical instrumentation
• Industrial process controls
• Strain gages
• Transducer interfaces
• Precision data acquisition systems
• Channel-isolated systems
• Portable instrumentation