A Power Transistor Gate Drive Circuit with Segment Drive Function

Abstract

The utility model relates to a grid drive circuit of a power tube with segment drive function, which belongs to the technical field of power management. Including the main control module, short pulse generation module and feedback clamping module, the main control module includes traditional inverter drive chain, power tube on and off circuit, used to control the power tube; short pulse generation module is used for grid voltage detection and Segment switching control, the pulse time is the positive short pulse signal and the negative short pulse signal when the power tube grid voltage rises from zero to the segment voltage; the feedback clamp module is used to control the charging current of the power tube grid, in the short pulse stage The feedback clamping module can provide small current charging for the power tube grid, and provide high current charging for the power tube grid after the short pulse to realize segmented driving. The invention is suitable for DC-DC converters, can balance high efficiency and EMI optimization of DC-DC converters, and has a simple implementation method.

Description

technical field [0001] The invention belongs to the technical field of power supply management, and in particular relates to a grid drive circuit of a power tube with segment drive function, which is used for driving an N-type power tube in a DC-DC converter. Background technique [0002] Power system energy conversion mainly relies on power switches and energy storage elements (inductors and capacitors). Power devices include traditional LDMOS devices and third-generation semiconductor devices, such as silicon-based GaN devices. In DC-DC converters such as Buck topology, the turn-on and turn-off process of power devices is affected by inductance as inductive clamp switching process (Clamp InductiveSwitching). In this mode, the turn-on and turn-off process of power transistors can be achieved through figure 1 The simplified circuit shown is analyzed, in which the role of the inductor is equivalent to a current source. In this mode, the turn-on process of switching power dev...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the EMI problem of the DC-DC converter due to the high gate charging current during the turn-on process of the power tube, as well as the shortcomings of the traditional segmented drive structure, which is difficult to implement, the present invention proposes a segmented drive function The gate drive circuit can be used to drive high-side power tubes and low-side power tubes in DC-DC converters. It adopts a segmented drive strategy and uses the gate charging current control technology (RGCC: Regulation of Gate Charging Current) to stage Regulate the gate charging current during the turn-on process of the power tube, realize the dv / dt slope of the switch node voltage change of the DC-DC converter, and optimize the di / dt slope of the power loop current change, and realize the purpose of optimizing the EMI of the DC-DC converter

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