Patent ID: 11916477
Assignee: WUXI CHIPOWN MICROELECTRONICS CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A voltage conversion circuit, comprising:
a switching power supply chip which comprises a power MOS transistor and a driving circuit, where the driving circuit is adapted to drive the power MOS transistor; and
a driving circuit power supply unit which comprises a boost unit, wherein when an output voltage of the boost unit is less than a working voltage of the driving circuit, an internal power supply of the switching power supply chip provides the working voltage for the driving circuit; and when the output voltage of the boost unit reaches the working voltage of the driving circuit, the output voltage of the boost unit provides the working voltage for the driving circuit;
wherein the switching power supply chip further comprises: a chip power pin, a chip ground pin and a chip auxiliary power pin;
wherein the driving circuit power supply unit further comprises a buffer unit, where an input end of the buffer unit is coupled to the chip power pin, and an output end of the buffer unit is coupled to a power input end of the driving circuit and the chip auxiliary power pin; and when the output voltage of the boost unit is less than the working voltage of the driving circuit, the internal power supply of the switching power supply chip provides the working voltage for the driving circuit through the buffer unit; and
wherein the buffer unit comprises a first MOS transistor, a gate of the first MOS transistor is coupled to a second output end of the control unit and is adapted to receive a second control signal from the second output end, a source of the first MOS transistor is coupled to the chip power pin, and a drain of the first MOS transistor is coupled to the power input end of the driving circuit and the chip auxiliary power pin.