level shift circuit suitable for a GaN high-speed gate drive circuit

Abstract

The invention discloses a level shift circuit suitable for a GaN high-speed gate drive circuit, and belongs to the technical field of power management. Gate drive control signal transmission is carried out by using a voltage-to-current-to-voltage structure, so that the rail-to-rail output capability is realized, and the situation of signal delay and even loss caused by the fact that the voltage ofa switch node of the GaN high-speed gate drive circuit is negative in dead time can be prevented; A dynamic current branch is adopted to carry out fast voltage transient protection, a common-mode transient noise interference resisting module is adopted to carry out anti-floating power supply rail dv/dt crosstalk protection, and the high CMTI capacity of an input end and an intermediate node of alevel shift circuit is achieved. A positive feedback latch module for limiting current is used for latching the current as an output maintaining structure. According to the level shift circuit, the transmission delay of the level shift circuit is reduced, high-speed signal transmission is realized, a low-resistance access and positive feedback are provided to prevent circuit output from being interfered by high dv/dt capability of the floating power supply rail, so that the high CMTI capability of the output end of the level shift circuit is realized, and the reliability of the circuit is improved.

Description

technical field [0001] The invention belongs to the technical field of power management, and in particular relates to a level shift circuit suitable for a GaN high-speed gate drive circuit. Background technique [0002] Since GaN power switching devices (such as GaN HEMT) have low gate charge Qg, low on-resistance R ds_on , high voltage resistance, no reverse recovery time and other good device physical characteristics, GaN power switching device high voltage half-bridge hard switching drive technology in high frequency, high power density power conversion applications (such as half bridge, full school, synchronous rectification BUCK converter, etc. ) becomes more and more important. High-speed, low power consumption, high CMTI (Common Mode Transient Immunity, ability to resist common mode transient noise interference) level shift circuit is very critical in the high-side drive circuit of the GaN power switching device drive circuit, because it determines the high-side Dri...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the requirements of the gate drive of GaN power switching devices on transmission speed, anti-common-mode transient noise interference capability and rail-to-rail output capability, and the shortcomings that traditional level shift circuits cannot be applied to the gate drive of GaN power switching devices, the present invention proposes a A high-speed level-shifting circuit, which can realize the anti-switching node voltage V in the half-bridge hard switching driving application of GaN power switching devices under the condition that the level-shifting circuit is guaranteed to realize ultra-low transmission delay SW for negative rail-to-rail output capability (at typical V SW =-2.5~-3V DC voltage can still achieve rail-to-rail output), and can achieve high immunity to common-mode transient noise interference (CMTI=50V / ns), suitable for GaN power switching devices half-bridge hardware switch drive application

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