Si8540 devices are non-isolated, unidirectional high voltage high-side current sense amplifiers for use in power management applications requiring current monitoring and current control loops, such as portable PCs, cellular infrastructure equipment, high-end routers, smart battery packs, and automotive applications. The Si8540 is an extremely cost-effective and flexible current sensor in a compact 5-pin SOT-23 package.
Our high-side DC current sensors measure the voltage drop across a sense resistor in the high voltage side of a line. Large values of current can be measured by using a small resistor value and keeping the series voltage drop low across the sense resistor. The Si8540 operates from a single supply +5 to +36 V and has a current output that can be converted to a ground referenced voltage with a resistor ROUT. The amplification factor of the current sense can be adjusted with a choice of external resistor ratios.