Avalanche tolerance testing circuit and method of power MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor)

Abstract

The invention relates to an avalanche tolerance testing circuit of a power MOSFET, which comprises a charging passage and a testing loop, wherein the charging passage consists of an adjustable DC (direct current) power supply, a rechargeable switch and an energy storage device; the testing loop consists of an energy storage device, an electric inductor and the power MOSFET to be tested; the positive electrode of the energy storage device is used for providing a voltage output signal for an avalanche state monitoring circuit so as to control the avalanche state monitoring circuit to output a first control signal and a second control signal; the control end of the rechargeable switch is used for receiving the first control signal output by the avalanche state monitoring circuit; and the grid electrode of the power MOSFET to be tested is used for receiving the second control signal output by the avalanche state monitoring circuit. The circuit provided by the invention is safe in operation, objective in test result and low in cost; due to the utilization of the energy storage device independent of the power supply, the energy is provided; the avalanche tolerance measurement can be realized by energy transfer; and the test for avalanche tolerance of high and temporary energy can be carried out.

Description

technical field [0001] The invention relates to a testing technology for a power MOSFET device structure, in particular to a testing circuit and method for avalanche tolerance when a power MOSFET device enters a breakdown voltage state. Background technique [0002] Power MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, Metal-Oxide-Semiconductor Field-Effect Transistor), as a power semiconductor device, is widely used in power electronics applications. The power MOSFET works in a forward bias state with majority carrier conduction, and is generally considered to be a device without secondary breakdown. In fact, when the power MOSFET is reverse-biased, affected by changes in electrical quantities such as drain voltage and current, the internal carriers will be multiplied in an avalanche, resulting in avalanche breakdown of the power MOSFET. [0003] A power MOSFET consists of several cells connected in parallel. Taking high-voltage VDMOS (Vertical Double-diffusing...

AI Technical Summary

Problems solved by technology

One disadvantage of this power MOSFET device avalanche energy tester is that the adjustable DC power supply is always involved in the test, and the adjustable DC power supply is disconnected only at the end of the test. If the source is short-circuited and the N-channel MOSFET does not disconnect the adjustable DC power supply from the test circuit in time, the adjustable DC power supply will short-circuit the MOSFET device under test through avalanche breakdown, causing serious damage to the test circuit and power supply system.

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