Description

The AD8220 is the first single-supply, JFET input instrumentation amplifier available in an MSOP package. Designed to meet the needs of high performance, portable instrumentation, the AD8220 has a minimum common-mode rejection ratio (CMRR) of 86 dB at dc and a minimum CMRR of 80 dB at 5 kHz for G = 1. Maximum input bias current is 10 pA and typically remains below 300 pA over the entire industrial temperature range. Despite the JFET inputs, the AD8220 typically has a noise corner of only 10 Hz.With the proliferation of mixed-signal processing, the number of power supplies required in each system has grown. The AD8220 is designed to alleviate this problem. The AD8220 can operate on a ±18 V dual supply, as well as on a single +5 V supply. Its rail-to-rail output stage maximizes dynamic range on the low voltage supplies common in portable applications. Its ability to run on a single 5 V supply eliminates the need to use higher voltage, dual supplies. The AD8220 draws a maximum of 750 μA of quiescent current, making it ideal for battery powered devices.Gain is set from 1 to 1000 with a single resistor. Increasing the gain increases the common-mode rejection. Measurements that need higher CMRR when reading small signals benefit when the AD8220 is set for large gains.A reference pin allows the user to offset the output voltage. This feature is useful when interfacing with analog-to-digital converters. The AD8220 is available in an MSOP that takes roughly half the board area of an SOIC. Performance for the A and B grade is specified over the industrial temperature range of −40°C to +85°C, and the W grade is specified over the automotive temperature range of −40°C to +125°C.Applications Medical instrumentation Precision data acquisition Transducer interfaces