High-Side Current Monitor Uses Low-Voltage AmplifierGreg Sutterlin; Cicie Wang

摘要

Telcom, LDMOS, automotive and many other applications require the measurement of current flow at high voltages (high-side current). Often, a circuit operating at 5 V must monitor currents at 48 V. Techniques using costly high-voltage difference amplifiers and other special devices can measure such currents, but the circuit in the figure performs the same function with a standard 5-V difference amplifier (U1), including provisions for gain adjustment.