Self-adaptive new soft-switching full-bridge circuit driving method and full-bridge driving circuit

Abstract

A drive method for a self-adaptive soft-switch full-bridge circuit, and a full-bridge drive circuit. The full-bridge drive circuit comprises a first switch device (1), a second switch device (2), a third switch device (3) and a fourth switch device (4). A first external control signal (DR3) is connected to a third control end of the third switch device, and a second external control signal (DR4) is connected to a fourth control end of the fourth switch device. A first node (M) is arranged on a connecting line between the first switch device and the third switch device, and a second node (N) is arranged on a connecting line between the second switch device and the fourth switch device. A first control end of the first switch device is connected to the second node, and a second control end of the second switch device is connected to the first node. The first node is connected to the second node via a loading loop (5) with an inductance characteristic. The drive circuit is simple in terms of circuit, is convenient for the implementation of a soft-switch function and is flexible in circuit layout.

Description

technical field [0001] The invention relates to the technical field of soft-switching full-bridge circuits, in particular to an adaptive novel soft-switching full-bridge circuit driving method and a full-bridge driving circuit. Background technique [0002] In the prior art, there are many kinds of full-bridge driving circuits, but all of them have many problems. Such as figure 1 Shown in is the auxiliary power supply bootstrap level-shift driving full-bridge circuit. The four bridge arms of the full-bridge circuit with this structure need to be directly connected to the drive control circuit, especially the upper arm also needs a high-voltage level-shift drive IC. , At the same time, an independent bootstrap power supply is required, the circuit is complicated, the cost is high, the noise is large, the loss is high, and the circuit layout is complicated. At the same time, due to the high voltage inside the driver IC, the performance and process requirements of the driver ...

AI Technical Summary

Problems solved by technology

like figure 1 Shown in is the auxiliary power supply bootstrap level-shift driving full-bridge circuit. The four bridge arms of the full-bridge circuit with this structure need to be directly connected to the drive control circuit, especially the upper arm also needs a high-voltage level-shift drive IC. , At the same time, an independent bootstrap power supply is required, the circuit is complicated, the cost is high, the noise is large, the loss is high, and the circuit layout is complicated

At the same time, due to the high voltage inside the driver IC, the performance and process requirements of the driver IC are high, the reliability may be affected, and it takes up volume and space, which brings troubles to the layout and installation of the circuit.

[0003] See figure 2 , figure 2 Shown in is the transformer-driven full-bridge circuit that is more commonly used at present. The transformer-driven full-bridge circuit with this structure has high cost of the transformer, and because the transformer isolates DC, the unipolar pulse on the primary side will be generated after being isolated by the transformer. Level shift (the problem of zero point shift), resulting in a serious imbalance in the driving voltage of the 4 arms, and it will be exacerbated as the duty cycle deviates from 50%, and a more complex shift or clamping circuit needs to be added to solve this imbalance The problem

In addition, there are parasitic distribution parameters between the windings of this circuit, which affects the performance, and the dead zone of this circuit is difficult to adjust, requiring complex processing circuits to complete, the cost is high, the effect is not good, and the difficulty of realizing soft switching increases.

Due to the large size of the transformer, a single transformer drives 4 bridges, and the circuit layout is very difficult, which is not conducive to the miniaturization, simplicity, high reliability and low noise of the product

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