High-side double-NMOS tube segmented driving system for GaN power tube

Abstract

The invention discloses a double-NMOS segmented driving circuit for a high-side GaN power tube. In the starting process of the high-side GaN power tube, a dVS / dt detection circuit detects a VS rising slope and converts the VS rising slope into a control voltage Vctr, the Vctr controls the rising speed of the grid voltage of a pull-up NMOS by controlling the magnitude of the output current of a voltage-controlled current source, and the voltage of the grid voltage of the pull-up NMOS is controlled by the control voltage Vctr; therefore, the size of the grid driving current of the GaN power tube in the Miller platform period is adjusted; when the end of the Miller platform is detected, the gate voltage of the NMOS is lifted and pulled up through the charge pump, the gate driving current of the GaN power tube is maximized, the complete opening of the GaN power tube is accelerated, small dv / dt noise is realized, the high opening speed of the high-side GaN power tube is ensured, the circuit structure is easy to realize, and the occupied area is small.

Description

technical field [0001] The invention relates to a drive circuit for high-side power devices in half-bridge driving, in particular to a dual NMOS tube segment drive system for high-side GaN (potassium nitride) power tubes, which belongs to the field of electronic technology and integrated circuit technology. Background technique [0002] The half-bridge gate drive circuit is widely used in motor drives, electronic ballasts, and DC / DC voltage conversion circuits. It is used to drive two high-side and low-side power switching devices connected in the form of totem poles to alternately conduct through to achieve output voltage regulation. Compared with the traditional use of silicon-based MOSFETs as high and low side power tubes, GaN power devices have the advantages of fast switching speed, high operating frequency, small on-resistance, and good temperature characteristics. GaN power devices are high-frequency, high-power-density , Ideal switching devices in high-efficiency po...

AI Technical Summary

Problems solved by technology

Although the bootstrap structure can solve the problem of pulling up the gate-source voltage V of the NMOS transistor GS The problem of decreasing as the output voltage increases, but it is necessary to increase the level conversion circuit inside the high-side drive circuit, and the integrated bootstrap diode greatly increases the area of ​​the chip

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