A digital synchronous rectification control method, device and switching power supply

Abstract

The invention discloses a digital synchronous rectification control method, a digital synchronous rectification control device and a switch power supply. The digital synchronous rectification control method comprises the steps of acquiring the driving signal DRQ1 of a first switch tube and the driving signal DRQ2 of a second switch tube in a digital half-bridge synchronous rectification circuit; when reaching the rising edges of the driving signal DRQ1 of the first switch tube and the driving signal DRQ2 of the second switch tube, triggering the driving signal SRQ3 of a third switch tube and the driving signal SRQ4 of a fourth switch tube in the digital half-bridge synchronous rectification circuit to open according to a preset opening time; and when reaching the failing edges of the driving signal DRQ1 of the first switch tube and the driving signal DRQ2 of the second switch tube, triggering the driving signal SRQ3 of the third switch tube and the driving signal SRQ4 of the fourth switch tube in the digital half-bridge synchronous rectification circuit to stop according to a preset closing time. The digital synchronous rectification control method is applicable to controlling digital synchronous rectification.

Description

Technical field [0001] The present invention relates to the technical field of power electronics, in particular to a digital synchronous rectification control method, device and switching power supply. Background technique [0002] With the continuous development of power electronics technology and the wide application of the Internet in various fields, the era of big data has arrived. The existing hardware equipment has been unable to meet market demand. A large number of servers are used, so high-performance, high-power server power supplies more and more important. [0003] The synchronous rectification control chip used in the prior art is as follows figure 1 Shown. When M1 is turned on, IC controls MOS tube SR2 to turn on; when MOS tube M2 is turned on, IC controls SR1 to turn on. The VS and VD feet of the IC in the picture are the non-inverting and inverting input terminals of the hysteresis loop comparator respectively. In this scheme, because the hardware synchronous rec...

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Problems solved by technology

In this solution, since the hardware synchronous rectification control chip controls the switch of the MOS tube through sampling, and the transformer secondary is a high-frequency concentrated area, the sampling signal is easily disturbed; and because the IC chip has requirements for high frequency, such as at high frequency It is easy to lose cycles, etc., and cannot meet the requirements of light load, heavy load, dynamic and other aspects at the same time, so that the control reliability of the entire synchronous rectification is not high

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