High-speed gate drive circuit for power LDMOS (laterally diffused metal oxide semiconductor)

Abstract

The invention belongs to the technical field of integrated circuits and the field of power electronics, and particularly relates to a high-speed gate drive circuit for driving a power LDMOS (Laterally Diffused Metal Oxide Semiconductor), which comprises an LDO module without an off-chip capacitor, a short pulse current source module and a driver module. Wherein the output of the short pulse current source module is connected to the power supply end or the floating end of the driver, and when the front-stage circuit gives a signal for turning on the power tube, short pulse current is injected to quickly turn on the power tube; and when the gate potential monitoring circuit in the short pulse current source module judges that the power tube is conducted, the control logic closes the short pulse current. In addition, the output of the LDO module without the off-chip capacitor is also connected to the power supply end or the floating end of the driver, so that the gate-source voltage of the power tube is finally stabilized at the accurate starting voltage. According to the low dropout regulator, the LDO free of the off-chip capacitor and capable of achieving fast transient response is combined with the short pulse current source, high-speed dynamic response is achieved, the starting time of a power tube is effectively shortened, meanwhile, external passive elements are saved, and the system structure is simplified.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits and the field of power electronics, and in particular relates to a high-speed gate drive circuit for power LDMOS. Background technique [0002] Today's portable electronic systems are getting smaller and smaller. In order to reduce the size of capacitive or inductive components, the operating frequency of power management circuits such as DC-DC or AC-DC converters must be increased, and off-chip components should be minimized. To meet the application of small volume, for small and medium power Buck converters, the power tube usually adopts the structure of high-side P-type and low-side N-type to avoid using bootstrap capacitors. As an indispensable part of the power management system, the gate drive circuit directly determines the maximum operating frequency of the converter. For the traditional gate drive circuit, in order to ensure a large slew rate of the drive circuit, usually LDO...

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Problems solved by technology

[0003] Aiming at the shortcomings of the above-mentioned traditional gate drive circuit with low working speed under a given core area, the present invention proposes a high-speed gate drive circuit for driving power LDMOS, which solves the problem of the existing traditional gate drive circuit. slow speed problem

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