Shunt-zero based on CMOS split-drain: A practical approach for current sensing

A current sensor circuit intended for integrated Smart-Power applications featuring galvanic Isolation is devised. It is based on magnetic detection using the CMOS compatible Split-Drain transistors (MAGFET) that provides linear output current versus magnetic field from DC to several MHz range. An integrated sensor built in 0.35 mu m CMOS technology presented an output conversion factor of 500nA/A, corner frequency around 1MHz and thermal spectral density of 60pA/root Hz for a power dissipation of less than 15mW.