Grid electrode protection circuit for field effect transistors connected in series

Abstract

The invention discloses a grid electrode protection circuit for field effect transistors connected in series. The grid electrode protection circuit comprises a circuit formed by series connection of more than one field effect transistor, grid electrodes of the field effect transistors are connected with a diode in series, a negative electrode of the diode is connected with the grid electrodes of the field effect transistors, a positive electrode of the diode is connected with a grid electrode control signal input terminal provided by the circuit in a unified manner, an equalizing resistor is connected between a drain electrode and a source electrode of each field effect transistor in parallel, and a voltage-releasing resistor is connected between the grid electrode and the source electrode of each field effect transistor in parallel. According to the circuit formed by series connection of more than one field effect transistor, the grid electrode of each field effect transistor is connected with one diode in series except for the grid electrode of the field effect transistor at a grounding terminal so that the problem that when the field effect transistors connected in series are turned off, the grid voltage is above the limit and causes breakdown is solved, the high-voltage-resistant range of the field effect transistors is extended, and the circuit can be widely applied in the photovoltaic, wind energy, and power electronics fields.

Description

technical field [0001] The invention relates to the field of electronic engineering, in particular to a field effect transistor series grid protection circuit. Background technique [0002] When the field effect tube is used as a switch, when the source and drain are disconnected, the voltage at both ends will increase. In some applications, the voltage between the source and drain will exceed its own withstand voltage limit. In order to solve this problem, it is necessary to replace the field effect tube with a higher withstand voltage, but this will cause some problems, such as the increase of power consumption non-linearity, the heating of the field effect tube will increase, the conduction voltage will increase, and there will be no higher withstand voltage. Field effect tubes are available for selection. In the face of these problems, only multiple FETs can be used in series to improve the overall withstand voltage level when they are turned off. [0003] After multip...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a field effect transistor series gate protection circuit, in order to solve the problem that the field effect transistor is broken down when the gate voltage exceeds the limit when the field effect transistor is connected in series

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