Patent ID: 9705317
Date: 2017-07-11
CPC Classifications: H02H,H02M,Y02B

Claim:
1. A power supply device, comprising: an energy storage unit configured to generate a driving voltage to a load circuit according to a supplied voltage; a first switch configured to selectively transmit the supplied voltage to the energy storage unit according to a first driving signal; a second switch configured to selectively conduct according to a second driving signal for adjusting the driving voltage; and a driving module configured to conduct the second switch when the supplied voltage rises at a first predetermined value, and generate the first driving signal and the second driving signal when the supplied voltage rises at a second predetermined value, wherein the first predetermined value is smaller than the second predetermined value, wherein when the power supply device boots up and the supplied voltage rises at the first predetermined value, the second switch conducts to transmit the supplied voltage to a ground via the second switch if the first switch is short-circuited, wherein the driving module includes: a pulse width modulation (PWM) controller configured to generate a PWM signal when the supplied voltage rises at the second predetermined value; and a driver configured to generate the first driving signal and the second driving signal according to the PWM signal, wherein the driver includes: a pre-overvoltage protection unit configured to adjust the second driving signal to transmit the supplied voltage to the ground via the second switch, when the supplied voltage rises at the first predetermined value.