Isolated analog amps are ideal for measuring voltage across a current shunt resistor

Silicon Labs Si8920 galvanically-isolated amplifiers are now available from Mouser stock. The device's low-voltage 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. The output is a differential analog signal amplified by either 8.1x or 16.2x, says the company. The very low signal delay of the Si8920 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. Exceptionally high common-mode transient immunity means that the Si8920 delivers accurate measurements even in the presence of high-power switching as is found in motor drive systems and inverters. The Si8920 isolated amplifier utilizes Silicon Labs' proprietary isolation technology. It supports up to 5.0kVrms withstand voltage per UL1577. This technology enables higher performance, reduced variation with temperature and age, tighter part-to-part matching, and longer lifetimes compared to other isolation technologies. Applications include industrial, HEV and renewable energy inverters, AC / Brushless and DC motor controls and drives, variable-speed motor control in consumer white goods, and isolated switch mode and UPS power supplies. Mouser also stocks the Silicon Labs Si890ISO-KIT Evaluation Kit which allows for quick connection to a shunt resistor to check out the functionality of the Si8920 isolated amplifier. The evaluation kit is populated with the Si8920BC-IP device. This allows for connection to a shunt resistor that produces up to ±200mV at full load. The kit features test points for monitoring the inputs, outputs, and supplies for the device. Surface mount component pads are available for input or output filtering circuits. The Si8920ISO-KIT evaluation kit demonstrates the functionality, the accuracy, the stability, and the low signal delay of the Si8920 amplifier.