A Dual-mode Buck Converter with Dynamic Sawtooth Voltage for Wide Input Voltage Range Application

A dual -mode buck converter with dynamic sawtooth voltage is presented in this paper. The proposed design can handle loads from 10 mA to 1000 mA by utilizing PSM and PWM modes. Moreover, there is hysteresis during mode switching from PWM to PSM to avoid the control mode fluctuating. Dynamic sawtooth voltage is used to address the line transition issue over a wide input voltage range. Implemented in 0.25 mu m BCD technology, this converter can generate an output voltage of 5 V with an input voltage range of 10-55 V. The simulated results demonstrate the proper mode transition under stepup/down load current transient. The peak efficiency is 92.57% at 90 mA. The load regulation and line regulation are 1.07 mu V/mA and 15.2 mu V/V, respectively.