All-gallium nitride integrated two-stage turn-off overcurrent protection circuit

Abstract

The invention belongs to the technical field of power semiconductor integration, and relates to an all-gallium nitride integrated two-stage turn-off overcurrent protection circuit. The circuit comprises a high-voltage isolation and detection circuit, a blanking and delay circuit, a judgment circuit, an adjustable clamping circuit and a hard turn-off bleeder circuit. The high-voltage isolation circuit and detection circuit is used for isolating the logic circuit from the bus voltage when being closed and realizing drain terminal voltage monitoring when working; the blanking circuit is used for shielding grid signal jitter when the device is started; the judgment circuit is used for judging an overcurrent signal; the time delay circuit is used for signal time delay; the controllable clamping circuit is used for generating adjustable clamping voltage; and the hard turn-off bleeder circuit is used for realizing quick turn-off of the device. The full gallium nitride integrated secondary turn-off overcurrent protection circuit can realize controllability of each stage in secondary turn-off, so that drain-source voltage overshoot generated when a gallium nitride power device is turned off can be better inhibited, and the full gallium nitride integrated secondary turn-off overcurrent protection circuit is compatible with a gallium nitride process platform.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor integration, and in particular relates to an all-gallium nitride integrated secondary turn-off overcurrent protection circuit. Background technique [0002] The enhancement mode gallium nitride high electron mobility transistor (GaN E-HEMT) can achieve relatively high charge density and mobility due to the high charge density and mobility of the two-digit electron gas (2DEG) generated by the heterojunction between the GaN layer and the AlGaN layer. higher efficiency and switching frequency. At the same time, compared with Si, GaN material has material advantages such as lower dielectric constant, higher critical breakdown electric field, higher thermal conductivity, etc., and has greater advantages in power conversion efficiency, volume and stability. Today, GaN HEMTs have been used in switching power supplies, electric vehicles, fast chargers, drive motors in aerospace, photovoltaic ...

AI Technical Summary

Problems solved by technology

However, due to the parasitic inductance L of the power device loop stray , the power device is turned off quickly, causing extremely high di / dt, resulting in a large overshoot voltage across the drain source of the device, which may cause breakdown of the power device

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