AD620 Instrumentation Amplifier

ADI’s AD620 comes in 8-lead SOIC and DIP packages and are low-cost, high-accuracy instrumentation amplifiers that, with an external resistor, allow the user to set gains of 1 to 10,000. The small footprint design and low power consumption (only 1.3 mA (maximum) supply current) make it a good fit for portable or remote applications that require a battery.

The AD620, with its high accuracy of 40 ppm (maximum) nonlinearity, low offset voltage of 50 µV (maximum), and offset drift of 0.6 µV/°C (maximum), is ideal for use in precision data acquisition systems such as weigh scales and transducer interfaces. Furthermore, the low noise, low input bias current, and low power of the AD620 make it well suited for medical applications such as ECG and noninvasive blood pressure monitors.

The low input bias current of 1.0 nA (maximum) is made possible with the use of Superϐeta processing in the input stage. The AD620 works well as a preamplifier due to its low input voltage noise of 9 nV/√Hz at 1 kHz, 0.28 μV p-p in the 0.1 Hz to 10 Hz band, and 0.1 pA/√Hz input current noise. Also, the AD620 is well suited for multiplexed applications with its settling time of 15 μs to 0.01%, and its cost is low enough to enable designs with one in-amp per channel.