Patent ID: 8274270

Claim:
An adaptive pulse width control power conversion method, wherein an input power source is converted by an adaptive pulse width control power conversion circuit into an output voltage supplied to a load, the power conversion circuit being switchable between a pulse frequency module (PFM) mode and a pulse width modulation (PWM) mode, the method comprising the following steps: (a) detecting a mode switching event signal; (b) upon detecting the mode switching event signal, the power conversion circuit generating a series of PFM control signals in accordance with a predetermined pulse width so as to supply a pulse width control signal; (b1) comparing pulse width of the PFM control signal and pulse width of a pulse width modulation (PWM) control signal generated by the power conversion circuit; (b2) identifying and supplying a greater one of the pulse widths of the PFM control signal and the PWM control signal as an output of the pulse width control signal; (c) using the pulse width control signal to control a switching circuit and employing a filter circuit to supply an output voltage to the load; (d) detecting a feedback status signal of the load; (e) sequentially adjusting pulse width of the PFM control signal from a low value to a high value according to a predetermined pulse width increment, and determining an optimum pulse width according to the feedback status signal; and (f) supplying the output voltage to the load in the PFM mode according to the pulse width adjusted optimum pulse width.