Patent ID: 8063684

Claim:
A pulse width modulated (PWM) controller applied to a switch-type voltage regulator, comprising: an error amplifier for receiving a reference voltage signal and a feedback voltage signal, and outputting an error current signal according to the received reference voltage signal and feedback voltage signal; a soft-start control circuit for outputting a compensating current signal according to at least one soft-start control signal; a compensating load for receiving the error current signal and the compensating current signal, and outputting a compensating signal according to the received error current signal and compensating current signal; and a comparator for receiving a ramp signal and the compensating signal, and outputting a pulse width modulated (PWM) signal; wherein the soft-start control circuit includes at least one bias current source and at least one control switch corresponding to the at least one bias current source, in which the bias current source generates a bias current corresponding to the error current signal, and the at least one control switch controls outputting of the bias current according to the at least one soft-start control signal so as to form the compensating current signal; wherein the soft-start control circuit outputs a largest value of the compensating current signal at the beginning of a soft-start control cycle; wherein the soft-start control circuit outputs a smallest value of the compensating current signal at the ending of the soft-start control cycle.