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

Claim 12:
13. A non-isolated power supply system, comprising: a rectifier unit, an output inductor, a feedback diode, and a voltage conversion circuit, the 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 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,
wherein an input end of the rectifier unit is coupled to an external Alternating Current (AC) power supply, an output end of the rectifier unit is coupled to a high-voltage input pin of the switching power supply chip of the voltage conversion circuit, and the rectifier unit is adapted to rectify the external AC power supply into a Direct Current (DC) which is input to the high-voltage input pin;
wherein an input end of the output inductor is coupled to the chip ground pin of the switching power supply chip, and an output end of the output inductor is coupled to an output end of the non-isolated power supply system;
wherein a positive electrode of the feedback diode is coupled to the output end of the non-isolated power supply system, and a negative electrode of the feedback diode is coupled to the chip power pin, which is adapted to feed back an output voltage of the non-isolated power supply system to the chip power pin; and
wherein the control unit further comprises: a third output end, which is coupled to a control signal input end of the boost unit and is adapted to control the boost unit to switch on or off, wherein when the output voltage of the non-isolated power supply system is high and a voltage of the chip power pin reaches a working voltage of the driving circuit, the third output end of the control unit outputs a third control signal to control the boost unit to switch off, and the chip power pin provides the working voltage for the driving circuit through the buffer unit of the switching power supply chip; and when the output voltage of the non-isolated power supply system is low and the voltage of the chip power pin is less than the working voltage of the driving circuit, the third output end of the control unit outputs the third control signal to turn on the boost unit and an output end of the boost unit provides the working voltage for the driving circuit.