Patent ID: 9647531
Date: 2017-05-09
CPC Classifications: H02M

Claim:
1. A soft-start switching power converter comprising: a rectifier circuit which receives an alternating-current (AC) voltage and which rectifies the AC voltage so as to generate a rectified voltage; a voltage converting circuit which includes a soft-start circuit which is connected electrically to the second terminal of said first switch for receiving the trigger signal, and which generates the control signal according to the trigger signal, said soft-start circuit determining during a start-up period whether or not to clamp a voltage level of the control signal at a preset voltage level based on whether a voltage level of the trigger signal is greater than a preset value, so as to turnoff said first switch, wherein the start-up period is proportional to a period of time required for the feedback voltage to increase to a preset starting voltage; wherein when the voltage level of the control signal is not clamped at the preset voltage level during the start-up period, the voltage level of the control signal rises from the preset voltage level.