Power supply circuit, control chip, switch power supply system and power supply method

Abstract

The invention discloses a power supply circuit, a control chip, a switch power supply system and a power supply method. The power supply circuit comprises a control unit, a switch unit, a capacitor and an MOS transistor, wherein the control unit is electrically connected with the input end of the switch unit and the gate electrode of the MOS transistor for generating a voltage signal for conducting or cutting off the MOS transistor and / or a current signal for conducting or cutting off the switch unit; the input end of the switch unit is further electrically connected with the direct current voltage input end of the switch power supply system; the output end of the switch unit is electrically connected to the capacitor and the drain electrode of the MOS transistor; the source electrode of the MOS transistor is coupled to the load end of the switch power supply system, wherein when the MOS transistor and the switch unit are conducted, the switch power supply system supplies power to the load; and when the MOS transistor is cut off according to the cut-off voltage signal output by the control unit, the switch unit is cut off according to the cut-off current signal output by the control unit or the switch unit is cut off after the capacitor is charged for a certain time.

Description

technical field [0001] The present invention relates to the field of switching power supply control, in particular to a power supply circuit, a control chip, a switching power supply system and its power supply method. Background technique [0002] High-side buck / buck-boost AC-DC switching power supplies are widely used in household appliances and electric meters. With the advancement of technology, the industry has higher and higher requirements for product performance, which requires higher efficiency and lower standby power consumption. , better EMI performance, better use flexibility, and lower cost. [0003] Power consumption during standby is divided into: dummy load (dummy load) consumption, control chip consumption, start-up circuit consumption, etc. The consumption of the control chip itself is determined by the control chip circuit and the power supply voltage of the control chip, so reducing the power supply voltage of the control chip can effectively reduce Sta...

AI Technical Summary

Problems solved by technology

High voltage direct power supply leads to the inability to reduce standby power consumption, low efficiency, and power triode cannot be used

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