This paper presents the use of a combined random pulse position modulation (RPPM)/digital pulsewidth modulation (DPWM) digital controller for a buck converter to simultaneously achieve low-conductive electromagnetic interference (EMI) and a fast transient response. An area-efficient RPPM/DPWM controller suitable for advanced system-on-chip integration is proposed and implemented in a field-programmable gate array-based prototype to verify its EMI-suppression capability. The experimental results for a 1.2-V digital buck converter show that the proposed digital switching regulator can switch between RPPM and DPWM modes smoothly and automatically. Closed-loop system measurements demonstrate that, compared to DPWM, up to 17.27 and 14.99 dB power spectra reductions are obtained in the input current and switching node, respectively.
All Science Journal Classification (ASJC) codes
- Control and Systems Engineering
- Electrical and Electronic Engineering