Voltage control method, three-segment driver and drive circuit

Abstract

The invention relates to the technical field of electronic circuits, and discloses a voltage control method, a three-section driver and a driving circuit. In the present invention, the voltage control method is used to control the gate-source voltage of the high-voltage MOS transistor of the switching power supply. The voltage control method includes: from the power supply voltage to the turn-on voltage V of the high-voltage MOS transistor TH Between, use strong drive to drive the high-voltage MOS transistor from the conduction state in the linear region to the conduction state in the saturation region; at V TH to the subthreshold voltage V TH‑ Between, use weak driving to slow down the rate of change of current in the high-voltage MOS tube; among them, V TH‑ than V TH The value is small; at V TH‑ To the lowest potential, a strong drive is used to drive the high-voltage MOS tube to completely cut off. In this way, while taking into account the overvoltage and EMC indicators, the switching speed can be increased and the dead time can be reduced, thereby significantly improving the efficiency of the switching power supply.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to a voltage control method, a three-segment driver and a driving circuit. Background technique [0002] With the increase in the functions of electronic products and the pursuit of higher performance, the power of the power supply is getting larger and wider, and the operating voltage range is getting wider and wider, which poses a higher challenge to the battery life and packaging of the power supply. Therefore, the conversion of the power supply Efficiency has higher requirements, and the factors affecting power supply efficiency are in addition to the on-resistance of the switch tube and the freewheeling tube, the DCR (DC resistance) of the inductor and the ESR (equivalent series resistance) of the capacitor, the switching speed, the dead zone Factors such as timing are also critical, and these mainly depend on the design of the drive circuit. The existing driver (D...

AI Technical Summary

Problems solved by technology

[0005] The switch of the MH tube and the ML tube is driven by an inverter composed of MPA, MNA, MPB, and MNB. In order to increase the switching speed, the only feasible way is to increase the driving capability of the inverter, but at the same time, the current passing through the power tube The rate of change increases, resulting in a strong overvoltage at the drain-source end of the power tube, and even breakdown of the power tube in severe cases

Therefore, the switching speed of the power tube cannot be effectively improved

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