High efficiency and low loss AC-DC power supply circuit and control method
AssigneeSilergy Semiconductor Technology (Hangzhou) LTD
InventorsChen Zhao, Jie Yao
Life of this patent
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Abstract
Disclosed herein are high efficiency, low loss AC-DC power supply circuits, and associated control methods. In one embodiment, an AC-DC power supply circuit can include: (i) a rectifier configured to rectify an AC power supply to generate a DC input voltage; (ii) a first stage voltage converter configured to convert the DC input voltage to a first output voltage, and to convert a first control signal to a feedback signal that represents the first output voltage; and (iii) a second stage voltage converter configured to convert the first output voltage to a constant DC output signal, where the first control signal represents a duty cycle of the second stage voltage converter.
Claims16
An AC-DC power supply circuit, comprising:
- a) a rectifier configured to rectify an AC power supply to generate a DC input voltage;
- b) a first stage voltage converter configured to convert said DC input voltage to a first stage output voltage, and to convert a control signal to a feedback signal that represents said first stage output voltage without using sampling resistors;
- c) a second stage voltage converter configured to convert said first stage output voltage to a constant DC output signal, and to generate said control signal that represents a duty cycle of said second stage voltage converter;
- and
- d) an output voltage feedback circuit in said first stage voltage converter and being configured to average said control signal, to compare said control signal against a reference value, and to generate said feedback signal via a compensation circuit to control a switch to convert said DC input voltage to said first stage output voltage.
A method of controlling an AC-DC power supply circuit, the method comprising:
- a) rectifying an AC power supply to generate a DC input voltage;
- b) converting said DC input voltage to a first stage output voltage through a first stage voltage converter;
- c) converting said first stage output voltage to a constant DC output signal, and generating said control signal, through a second voltage converter;
- d) converting, without using sampling resistors, a control signal to a feedback signal that represents said first stage output voltage, wherein said control signal represents a duty cycle of said second stage voltage converter;
- and
- e) averaging said control signal, comparing said control signal against a reference value, and generating said feedback signal through compensation to control a switch for converting said DC input voltage to said first stage output voltage.
Dependencies are inferred from the claim text.