An igbt drive circuit

Abstract

An IGBT driving circuit belongs to the technical field of electronic circuits. In the turn-off stage, variable slope driving is adopted, and the turn-off process is divided into two stages through the special size design of the resistor R and the fifth inverter INV5. From T2 to T3, only the first NMOS transistor MN1 is turned on, and the circuit is in a slow state. The discharge state is conducive to improving the overshoot voltage and solving the problem of surge voltage generated during the turn-off period; from T3 to T4, after the delay designed by the resistor R and the fifth inverter INV5, the second NMOS transistor MN2 is turned on , the circuit enters a fast discharge state, which accelerates the turn-off process of the entire IGBT, reduces switching losses, and increases the discharge current, which greatly reduces the tailing time; the invention does not require an additional RC passive absorption network, avoiding the traditional RC absorption The damping loss caused by the loop; because the pull-down capability of the drive circuit during the turn-off process is guaranteed, and the resistance value of the latter stage is low, the circuit can resist higher dv / dt and improve the electromagnetic interference characteristics of the overall circuit.

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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