The Si8920 is a galvanically isolated analogue amplifier. Their low voltage and differential input is ideal for measuring voltage across a current shunt resistor or for any place where a sensor must be isolated from the control system.

Output is a differential analogue signal amplified by either 8.1x or 16.2x. The very low signal delay allows control systems to respond quickly to fault conditions or changes in load. Low offset and gain drift ensure that accuracy is maintained over the entire operating temperature range.

High common mode transient immunity means that the Si8920 will deliver accurate measurements even in the presence of high power switching like would be found in a motor drive system or inverter.

To help evaluate the Si8920 there is a dedicated development kit available - SI8920ISO-KIT (RS 9026806). It is populated with the Si8920BC-IP and enables quick connection to a shunt resistor.

The Si8920 is available in 4 variants:
Si8920AC-IP (RS 901-3967) with an input range of ±100 mV in a Gull-Wing DIP-8 package
Si8920BC-IP (RS 901-3976) with an input range of ±200 mV in a Gull-Wing DIP-8 package
Si8920AD-IS (RS 901-3979) with an input range of ±100 mV in a SOIC-16 package
Si8920BD-IS (RS 901-3973) with an input range of ±200 mV in a SOIC-16 package

Current Sensing Amplifiers have a voltage output that is proportional to the volt drop across a very low value resistor, usually in a high-current power rail. Hence they measure the current flowing in that power rail.