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

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.