Novel digital multi-phase duty cycle modulation methods for voltage regulators

For digitally controlled voltage regulator (VR), high resolution, high switching frequency digital pulse-width modulator (DPWM) is required. With conventional constant frequency modulation method, ultra high clock frequency is needed, which will consume unaffordable power. This paper proposes a pseudo-dither method based on digital constant on-time modulation to achieve high duty cycle resolution in multiphase application without adding too much hardware cost. About 10 times higher improvement on resolution can be gained in VR application. Experiment results verify the proposed method.