AD620 is a low-cost, high-precision instrumentation amplifier. It only needs an external resistor to set the gain. The gain range is 1 to 10,000. In addition, AD620 adopts 8-pin SOIC and DIP package, the size is smaller than the discrete circuit design, and the power consumption is lower (the maximum operating current is only 1.3mA), so it is very suitable for battery-powered and portable (or remote) applications. AD620 has the characteristics of high accuracy (maximum non-linearity 40ppm).