Delay-time suppression technique for DC/DC buck converter using voltage mode PWM control

Abstract

This paper proposes a delay-time suppression technique in a DC/DC buck converter with voltage mode PWM control for fast response to its load change. Sudden load current change is detected through a high pass filter at the converter output, which turns on the power transistor switch in a DC/DC converter instantaneously. Then the control time-delay is suppressed and quick response is realized. Our circuit simulation shows that using the proposed circuit, the undershoot/overshoot voltage at the output is suppressed significantly, compared to the conventional circuit. We have compared the undershoot/overshoot voltages with multi-phases, and the sudden load current changes with frequency. Furthermore, we have compared undershoot/overshoot voltages with load current.