A 10-MHz Current-Mode Fixed-Frequency Hysteretic Controlled DC-DC Converter With Fast Transient Response

Abstract

This paper proposes a fixed-frequency current-mode hysteretic controlled DC-DC buck converter operating at 10 MHz. The proposed converter senses the inductor current through a current-sensing filter and compares the sense-node voltage with only one threshold of the hysteretic comparator. The reference clock synchronizes the switching frequency of the converter by forcedly altering the present state of the hysteretic comparator. The proposed converter is targeted to switch at a frequency of 10 MHz with the output filter components of L=200 nH and C=4.7 µF. The simulation results show that the maximum overshoot and the settling time are below 12 mV and 1.9 µs respectively while the load changes from 50 mA to 450 mA within 1 ns time. The output voltage load regulation is 2.5 mV/A.