Step level output circuit

Abstract

The invention relates to a step level output circuit, comprising a reference source circuit, an intermediate level drive circuit, a control circuit, a first P type transistor, a first N type transistor and a second N type transistor. The intermediate level drive circuit comprises a current source, a second P type transistor, a third N type transistor and a capacitor. A threshold voltage Vthp of the second P type transistor, the threshold voltage Vthn of the second N type transistor, an intermediate voltage V1 output by an output end of the step level output circuit and a reference voltage VF output by the reference source circuit have the following relationship: VF=V1+Vthn-Vthp. Through adoption of the circuit of the structure, the output response is fast, the circuit is applicable to bandwidth application of a wide range, the structure is concise, a maintenance current is low, only three drive tubes are required, an area of a chip is reduced, a cost performance ratio is improved, and moreover, the fast response feature is kept, and the application range is wide.

Description

technical field [0001] The present invention relates to the technical field of gate drive, in particular to the technical field of step-level gate drive, in particular to a step-level output circuit. Background technique [0002] In the driving circuit, especially in the driving of the IGBT, the driving IC is usually used to generate the pulse voltage to drive the gate of the IGBT, such as figure 1 As shown, in some applications, the driver IC sometimes needs to generate a step level to drive the IGBT (or MOS tube), such as figure 2 shown. The signal driving the IGBT (or MOS tube) rises to a set level first, and then jumps to the VCC level after a period of time. [0003] Generally, there are two ways to realize the above functions: [0004] Implementation method one, such as image 3 As shown, the reference source module outputs the reference voltage V1, and the op amp is used in the follower mode. The input reference voltage signal at the forward end of the op amp is ...

AI Technical Summary

Problems solved by technology

The response speed of this structure is better than that of method 1, but because the V1 generated by the voltage source circuit needs a strong driving capability, the output tube of the voltage source circuit needs to be made larger, and the switch tubes P31, P32 and N32 also need Low on-resistance, so this structure requires a large area of ​​output transistors to meet the requirements of the drive output, and the cost performance is very low

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