Synchronous rectification driving circuit suitable for central tapped structure rectifying circuit

Abstract

The invention discloses a synchronous rectification driving circuit suitable for central tapped structure rectifying circuit, comprising a high frequency transformer T1, a current transformer CT1, an output capacitor C1, an output capacitor C1, a synchronous rectifying tube SR1, a synchronous rectifying tube SR2 and a driving circuit for driving the synchronous rectifying tube SR1 and the synchronous rectifying tube SR2, wherein the current transformer CT1 has two primary side windings N1, N2 and one secondary side winding N3, which can drive two synchronous rectifying tubes. The favourable effects of the invention are as follows: 1, it only needs one currant transformer and one secondary side winding to realize the driving of two SRs so as to simplify the circuit and reduce the cost; and thus it is good for the high frequency and integrated development; 2, it is able to realize supplying power by itself of the driving circuit; the driving is simple; 3, it reduces the driving power consumption of the synchronous rectification, improves the light loading efficiency, reduces the loss and lowers the cost.

Description

technical field [0001] The invention relates to a synchronous rectification driving circuit. More specifically, the present invention relates to a current-controlled synchronous rectification driving circuit suitable for a center-tap structure rectification circuit. Background technique [0002] In order to reduce the power consumption of integrated circuits, the power supply voltage will be further reduced, and more and more low-voltage and high-current power supplies will be used. With the advancement of semiconductor technology, the on-resistance of low- and medium-voltage MOSFETs is getting smaller and smaller. Therefore, in low-voltage and high-current switching power supplies, in order to reduce the conduction loss, synchronous rectification technology is generally used. [0003] Synchronous rectification technology can be divided into voltage drive and current drive according to its drive signal type. Different topologies have different driving methods in the voltag...

AI Technical Summary

Problems solved by technology

In the existing technology, the synchronous rectifier tube of the center-tap rectification circuit driven by the current driving method needs two current transformers as independent sampling and driving, and the cost is relatively high

Moreover, since the current transformer is connected in series with the synchronous rectifier tube, the transformer itself has some leakage inductance, which resonates with the junction capacitance between the drain and source of the MOSFET, causing voltage spikes, increasing online losses, and reducing efficiency

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