A fully integrated DC to 75 MHz current sensing circuit with on-chip Rogowski coil

摘要

A wide-bandwidth galvanically isolated current sensing circuit with an integrated Rogowski coil in 180 nm CMOS is presented. Exploiting the high-frequency properties of an optimized on-chip Rogowski coil, currents can be measured up to a bandwidth of 75 MHz. The analog sensor front-end comprises a two-stage integrator, which allows a chopper frequency below signal bandwidth, resulting in 2.2mVrms output noise. An additional integrated Hall sensor extends the measurement range towards DC.