A Fast Transient Response Slope-Adjusted Voltage Mode Buck Converter

This work proposes a fast transient-response fixed-frequency slope-adjusted voltage mode (SAVM) control scheme for DC-DC converter design. Compared with conventional voltage mode control, this proposed scheme adjusts converter duty cycle directly from feedback signal path, instead of from the slow compensation path, therefore improving transient speed significantly. A 5V-to-1V buck converter was implemented using CSMC 0.5um BCD process. Simulation results show that the converter achieves a bandwidth up to 803 KHz with 3 MHz switching frequency. Besides, the undershoot voltage and recovery time is 12mV and 4us, respectively, under a load transition from 2A to 3A.