A 2 MHz buck converter with dual-mode control for Power Management Unit

A monolithic dual mode buck dc-dc converter is proposed in this paper. The converter operates in Peak-Current-Mode Pulse-Width-Modulation (PWM) with a 2 MHz switching frequency under the heavy load condition. And an Adaptive-On-Time Pulse-Frequency-Modulation (AOTPFM) is employed to suppress the output ripple voltage variations under the light load condition. The DC-DC converter has been implemented in a 0.35 µm CMOS process and measured. The peak efficiency reaches 93% and stay over 78% for load range from 10 mA to 2000 mA with the dual mode control.