Power switch system and method for judging whether complementary switch is in soft switch state or hard switch state

Abstract

The invention relates to a power switch system and method for determining whether a complementary switch is in a soft switch state or a hard switch state. A first switch and a second switch are connected in series between a first reference node and a second reference node, the first reference node and the second reference node have different potentials to drive the complementary first and second switches to be alternately turned on. When one of the first and second switches is turned on, the other one is turned off and cannot be turned on at the same time. Dead time is set between the turning-on period of the first switch and the turning-on period of the second switch. The potential reversing time mode at an interconnection node of the first switch and the second switch is detected. The reversing time node is earlier than the termination period of the dead zone time in each switching period, which represents that the switch is in the soft switching state. The reversing time node is later than the termination period of the dead time in each switching period, which represents that the switch is in the hard switching state.

Description

technical field [0001] The present invention mainly relates to the driving field of a power switch, and more precisely relates to a scheme for driving a power switch that can more accurately discriminate whether the switch is in a hard switching state or a soft switching state. Background technique [0002] Switching tubes refer to transistors as switching devices, mainly including bipolar transistors, metal-oxide field effect transistors, insulated gate bipolar transistors, and the like. When designing a switching power supply, the loss of the switching tube is an important indicator. Reducing the loss can improve the efficiency and power density of the system, and can also reduce the volume of the cooling device, making the switching power supply miniaturized and prolonging the service life of the switching power supply. Switching tube loss is usually divided into three parts: turn-on loss, turn-off loss and conduction loss. The conduction loss includes two parts: the co...

AI Technical Summary

Problems solved by technology

The defect of this technology is: the value of the inductance and capacitance components used for energy exchange and transmission is large, which is not conducive to the miniaturization of the circuit; the circuits for energy exchange and transmission are many and not simple, resulting in a large mutual influence of the buffer circuit and a large dependence on circuit parameters , the soft switching element parameters depend on the circuit conditions, and the design is very complicated; at least two inductors must be added, these inductors are prone to large voltage spikes, and the loss is much larger than that of capacitors

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