Patent ID: 8723497

Claim:
A COT (Constant-On-Time) generation circuit for generating a turn-on signal to a buck converter for converting an input voltage to an output voltage, comprising: a capacitor; a current source having a transfer impedance and coupled to a first voltage for generating a current according to a first resistance of the transfer impedance and the first voltage; a second resistor coupled between the capacitor and the current source; an inverter coupled to a first front-end driver signal of the buck converter for inverting the first front-end driver signal; a transistor including a drain coupled to the capacitor, a source coupled to a ground terminal and a gate, for receiving the inverted first front-end driver signal to trigger the current source charging the capacitor so as to generate a set turn-on signal; 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 including a reset input terminal coupled to the output terminal of the comparator, and a set input terminal coupled to a trigger signal of the buck converter, for outputting a turn-on signal to a driver stage circuit of the buck converter according to the trigger signal and the comparison result.