Constant-on-time generation circuit and buck converter

摘要

A constant-on-time generation circuit for generating a turn-on signal to a buck is disclosed. The constant-on-time generation circuit includes a capacitor, a current source, a second resistor, an inverter, a transistor coupled to the inverter for generating a set turn-on signal according to a first front-end driver signal of the buck converter, a comparator including a negative input terminal coupled to a reference voltage, a positive input terminal coupled to the second resistor and the current source, and an output terminal, for comparing the reference voltage with the set turn-on signal to output a comparison result, and an SR-latch for outputting a turn-on signal to a driver stage circuit of the buck converter according to a trigger signal of the buck converter and the comparison result.