Digitally controlled low-EMI switching converter with random pulse position modulation

Abstract

A fully digital controlled low-EMI switching converter combining RPPM (Random Pulse Position Modulation), our improved version of Hybrid DPWM (Digital Pulse Width Modulator) and AEDPWM (Area-Efficient DPWM) schemes is proposed to achieve low-EMI (Electromagnetic Interference) with reduced area and power consumption. A FPGA-controlled prototype buck converter operating at 1 MHz switching frequency with 1.8 V input voltage and 0.6–1.2V output voltage is presented to demonstrate the technique. The resulting switching noise suppression capability is up to 18 dB in average.