A 94.3 % Peak Power Efficiency Time-Based Buck Converter Using Pulse-Phase-Shift Modes with An Intrinsic Window for Transient Enhancement

This paper proposes a time-domain controlled buck converter with fast transient response. The dual-mode control consisting of pulse-width modulation (PWM) and pulse phase shift-pulse train (PPS-PT) modes is utilized to suppress the voltage ripples during the steady state and enhance the transitions between the light and heavy load, respectively. The edge-pursuit comparator (EPC) is adopted to detect the voltage difference and decide the operation mode when the load varies. Compared with conventional hysteretic window control, lower power consumption, and better transient response are achieved. Measurement results show that when the load varies from 50 mA to 450 mA, the recovery time is 2.5 μs and the undershoot is 100 mV. The overall peak power efficiency is 94.3 % and a FoM of 1.68 mA*%/μs*mV is accomplished.