Patent ID: 7978487
Filing Date: 2011-07-12
Classification: H02H,H02M

Abstract:
1. A switching power supply, comprising: an energy-storing device, coupled to an input power source; a power switch with a control terminal, for controlling the energy-storing device to increase or decrease electric power within the energy-storing device; a driving circuit, coupled to the control terminal of the power switch, for switching the power switch; and a thermal sensing device, coupled to the control terminal of the power switch and powered by the driving circuit; wherein the thermal sensing device disables the driving circuit when sensing that an ambient temperature exceeds a predetermined range, the driving circuit is placed in an integrated circuit chip which comprises an oscillator and a pin, the oscillator provides a periodic signal to the driving circuit, the switching power supply further comprises a resistor coupled to the oscillator via the pin of the integrated circuit chip, and the thermal sensing device is coupled between the resistor and the control terminal of the power switch.