Silicon Labs Current Sensor Si8540

The Si8540 is a complete, uni-directional, high voltage high-side current sense amplifier for use in portable PCs, cellular infrastructure equipment, high-end routers, smart battery packs, automotive applications and other power management applications that require current monitoring and current control loops. The Si8540 is designed to be an extremely cost-effective, value-added current sense amplifier that has low power requirements, can sense a wide range of currents with different resistor values and comes in an extremely compact 5-pin SOT-23 or 8-pin SOIC package. The Si8540 measures 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. Overview Bottom Content Features +5 to +36 V supply operation 0.2% full scale accuracy 90 μA max supply current 9 μA shutdown current -40 to +85 ºC