SWITCH CONTROL CIRCUIT AND BUCK CONVERTER COMPRISING THE SAME

摘要

A buck converter includes a power switch having a first end to receive an input voltage, a synchronous switch connected between a second end of the power switch and the ground, an inductor having a first end connected to the other end of the power switch, and a switch control circuit configured to turn off the synchronous switch when a zero voltage delay time passes after an inductor current flowing through the inductor reaches a predetermined reference value, calculate a dead time based on the input voltage and the zero voltage delay time, and turn on the power switch when the dead time passes following the turn-off time of the synchronous switch.

主权项

1. A switch control circuit for a power switch and a synchronous switch that are connected to an inductor, the switch control circuit comprising:
a comparator configured to compare a detection voltage for detecting an inductor current flowing through the inductor with a predetermined reference voltage; a delay unit configured to delay an output of the comparator by a zero voltage delay time; and a dead time calculation unit configured to calculate a dead time based on the zero voltage delay time and an input voltage that is input to the power switch, wherein the switch control circuit is configured to control a turn-off time of the synchronous switch according to an output of the delay unit, and turn on the power switch when the dead time passes following the turn-off time of the synchronous switch.