Title:
CONTROL METHOD AND CONTROL CIRCUIT FOR BUCK CONVERTER
Document Type and Number:
WIPO Patent Application WO/2023/020407
Kind Code:
A1
Abstract:
The present invention relates to the technical field of switch power supplies. Disclosed are a control method and control circuit for a BUCK converter. The control method is mainly used for solving the problem of a low efficiency in a DCM operating mode due to it being difficult for a main power switch tube to achieve a ZVS caused by the insufficiency of a negative current provided by a power inductor in the DCM operating mode. The control method is mainly implemented by means of a digital control scheme. The method comprises: an inductor current sampling circuit detecting a zero-crossing signal of a current of an inductor, and sending the zero-crossing signal to a DSP; the DSP receiving the zero-crossing signal, and performing counting; when a count value n ≥ 2, the DSP sending a synchronous rectifier tube switching-on signal, such that a synchronous rectifier tube is switched on; an output capacitor reversely charging a power inductor, such that a negative current of the inductor is increased; and when the negative current is increased to a given value, switching off the synchronous rectifier tube, and switching on a main power tube after a dead time, such that the main power tube can achieve a ZVS.
Inventors:
YANG ZHI (CN)
CHEN YAO (CN)
PAN CHENGZHANG (CN)
CHENG ZHIYONG (CN)
CHEN YAO (CN)
PAN CHENGZHANG (CN)
CHENG ZHIYONG (CN)
Application Number:
PCT/CN2022/112347
Publication Date:
February 23, 2023
Filing Date:
August 15, 2022
Export Citation:
Assignee:
MORNSUN GUANGZHOU SCI & TECH (CN)
International Classes:
H02M3/158; H02M1/00; H02M1/088
Foreign References:
| CN113809920A | 2021-12-17 | |||
| CN106033929A | 2016-10-19 | |||
| CN108696132A | 2018-10-23 | |||
| US20170077815A1 | 2017-03-16 |
Attorney, Agent or Firm:
GUANGZHOU ZHIYOU PATENT & TRADEMARK AGENCY CO., LTD. (CN)
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