Narrow pulse driver of insulation bar power tube

Abstract

The invention relates to field of MOSFET,IGBT drive circuit, specially a kind of MOSFET,IGBT narrow pulse driver which is electricity separated and without separating power source, the driver includes three parts: Signal transforming and drive, pulse transformer, electronic switch. The signal transforming circuit transforms the high or low level of input signal to high narrow pulse or low narrow pulse with definite frequency, the input signal is modulated by the high frequency narrow pulse signal, the power tube drives the pulse transformer, and charges the gate of the power tube under the control of electronic switch to form positive pressure or negative pressure. When the narrow pulse signal is generated, the electronic switch is opened, when it is diminished, the electronic switch is closed. It uses the gate capacitance to maintain gate pressure, because it adopts the narrow pulse drive, the capacity of the pulse transformer is small, without separating power source, and can maintain the dredge or cut off of the power tube.

Description

technical field [0001] The invention relates to an insulated gate power transistor (MOSFET, IGBT) and the field of a grid drive circuit, in particular to a narrow pulse driver for an insulated gate power transistor. Background technique [0002] Insulated gate power transistors, such as MOSFETs and IGBTs, are driven by voltage and require a dedicated driver. There are two main types of products at present: one is that the input signal and output drive circuit are isolated by optocouplers and powered by an isolated power supply. Due to the need to isolate the power supply, the cost is high, the circuit is complicated, and the design and use are inconvenient. The other is that the input and output are not electrically isolated, and the power supply uses a bootstrap power supply driver. Although this kind of driver does not need to isolate the power supply, it has poor anti-interference ability due to no electrical isolation, and is prone to overvoltage breakdown. After the b...

AI Technical Summary

Problems solved by technology

Although this kind of driver does not need to isolate the power supply, it has poor anti-interference ability due to no electrical isolation, and is prone to overvoltage breakdown. After the breakdown, DC high voltage enters the low-voltage circuit, which has poor reliability and cannot maintain the power tube on and off all the time.

[0003] In addition, there is another circuit that directly drives the grid of the power tube by the isolation transformer. Although the isolation power supply is not required, the volume of the transformer has high requirements for the input signal and signal duty cycle, especially when the frequency is low. Larger and therefore less practical

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