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 driving, in particular to the technical field of step-level gate driving, 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 a 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 driving IGBT (or MOS tube) signal rises to a set level first, and then jumps to the VCC level after a period of time. [0003] There are usually two ways to achieve the above functions: [0004] Implementation method one, such as image 3 As shown, the reference source module outputs a reference voltage V1, and the op amp is used in a follower mode. The input reference voltage signal at the forward end of the op amp is switched by a switch,...

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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