Patent ID: 8624574

Claim:
A Pulse Width Modulation (PWM) controller of a DC-DC converter, comprising: an error amplifier, receiving a reference voltage and a feedback voltage corresponding to an output voltage of the DC-DC converter to provide an error signal; a compensation unit coupled to an output of the error amplifier, compensating the error signal and comprising a first resistor and a first capacitor, wherein the capacitor is coupled between the first resistor and a ground; a ramp generator, generating a ramp signal according to an on time signal; a first comparator coupled to the compensation unit and the ramp generator, wherein when the compensated error signal exceeds the ramp signal, the first comparator generates a trigger signal, wherein the compensation unit causes an included angle between the compensated error signal and the ramp signal to increase; and a PWM generator coupled to the first comparator, providing the on time signal according to the trigger signal, an input voltage of the DC-DC converter and the output voltage of the DC-DC converter.