Patent ID: 7256632

Claim:
A pulse width modulation (PWM) controlling module comprising: a PWM controller for generating a PWM signal, the PWM signal being utilized for controlling a supply voltage applied to an electronic system; a load detector, coupled to the PWM controller, for detecting a load of the electronic system according to the PWM signal and generating a decision value accordingly; and an adjusting module, coupled to the PWM controller and the load detector, for controlling the PWM controller to adjust the PWM signal according to the decision value, the adjusting module comprising: a storage unit for storing a plurality of predetermined values; a logic circuit, coupled to the load detector and the storage unit, for comparing the decision value with a first predetermined value to generate a control signal utilized to control the PWM controller; and a reference voltage generator, coupled between the logic circuit and the PWM controller, for adjusting a reference voltage utilized by the PWM controller according to the control signal.