EMI resisting voltage regulator with large signal PSR up to 1GHz

Abstract

A voltage regulator is introduced that exhibits large signal (25 dBm) power supply rejection (PSR) up to 1GHz to comply with current electromagnetic compatibility (EMC) standards [1]. Negative peak cut-off using a rectifying diode is demonstrated so that line disturbances of several volts can be tolerated while still maintaining positive drop-out voltage. In order to avoid electromagnetic interference (EMI) at the output the regulator is realized in an output capacitor-less topology, thus decoupled only internally by a 200 pF on-chip capacitor. The regulator was implemented in 0.18 μm HV CMOS and draws a quiescent current of 240 μA at 4V supply while delivering up to 5mA load current at a nominal output of 3.3V.