IGBT drive circuit

Abstract

The invention discloses an IGBT drive circuit and belongs to the technical field of an electronic circuit. In a switch-off phase, variable-slope drive is employed; a switch-off process is divided into two phases through special size design of a resistor R and a fifth inverter INV5; in the T2 to T3 phase, only a first NMOS transistor MN1 is switched on, and the circuit is in a slow discharge state, so overshoot voltage is improved and the surge voltage problem occurring in a switch-off period is solved; and in the T3 to T4 phase, a second NMOS transistor MN2 is switched on after delay time designed through the resistor R and the fifth inverter INV5, the circuit enters a fast discharge state, the switch-off process of the whole IGBT is accelerated, switch losses is reduced, a discharge current is increased, and the trailing time is greatly reduced. According to the circuit, an extra RC passive absorption network is unnecessary; the damping losses resulting from a traditional RC absorbing circuit are avoided; the pull-down capability of the drive circuit of the switch-off process is ensured; a resistance value in the latter stage is relatively low, so the circuit is high in dv / dt resistance; and the electromagnetic interference property of the integrated circuit is improved.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits, and in particular relates to a drive circuit suitable for IGBT proposed by combining the characteristics of IGBT devices. Background technique [0002] IGBT gate drive integrated circuit is one of the typical circuits of HVIC (high voltage integrated circuit). Due to its high reliability, small area and high effect, it is widely used in household appliances and industrial equipment, aviation, aerospace, weapon systems, etc. An important part of HVIC is the driving control of IGBT, but unreasonable driving will produce high dv / dt and di / dt, and high dv / dt and di / dt switching drive poses a great challenge to the reliability of IGBT , can easily lead to damage to the IGBT. [0003] The main reason for IGBT performance attenuation or even damage is that the IGBT turn-off mechanism and the change law of voltage and current during the turn-off process are unclear, which leads to the inabil...

AI Technical Summary

Problems solved by technology

[0005] What the present invention aims to solve is to propose an IGBT drive circuit in combination with the characteristics of the IGBT device, which adopts variable slope driving in the turn-off phase, and solves the long current tail during the turn-off period without the need for an additional RC passive absorption network. And the problem of surge voltage generated, while improving the circuit anti-dv / dt and di / dt characteristics, reducing the overshoot voltage during the turn-off process and improving the overall electromagnetic interference characteristics

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