Buck converting controller for reduction of output voltage overshoot

摘要

A buck converting controller, adapted to control a DC-DC buck converting circuit to convert an input voltage into an output voltage, is disclosed. The buck converting controller comprises a feedback control circuit, an off-time determination circuit and a load control circuit. The feedback control circuit turns on and off a high-side transistor and a low-side transistor of the DC-DC buck converting circuit in response to a feedback signal indicative of the output voltage. The off-time determination circuit determines a preset off-time period according to the input voltage and the output voltage and generates an off notice signal according to the preset off-time period. The load control circuit is coupled to the DC-DC buck converting circuit and determines whether to release an electronic energy stored in the DC-DC buck converting circuit according to the off notice signal.

主权项

1. A buck converting controller, adapted to control a DC-DC buck converting circuit to convert an input voltage into an output voltage, comprising:
a feedback control circuit, controlling a high-side transistor and a low-side transistor of the DC-DC buck converting circuit to be turned on and off according to a feedback signal indicative of the output voltage; an off-time determination circuit, determining a preset off-time period according to the input voltage and the output voltage, and generating an off notice signal according to the preset off-time period; and a load control circuit, generating an overshoot preventing signal according to the off notice signal; wherein, the feedback control circuit controls the low-side transistor to be cut off when receiving the overshoot preventing signal.