Automatic sorting circuit based on the parallel use of SiCMOSFET device, and automatic sorting method

Abstract

The invention discloses an automatic sorting circuit based on the parallel use of the sic MOSFET devices. A power supply unit I supplies power to the drain electrode of the device through a series load, a current monitoring unit I is used for measuring the current passing through the device, and the driving unit I provides required modulation driving for the device. A power supply unit II suppliespower to Q1 through a constant current source, and the grid electrode of the Q1 is connected with a driving unit II. A current monitoring unit II is used for measuring the current passing through theQ1, and the driving unit II is used for providing driving for the Q1, and is in signal synchronization with the driving unit. A voltage monitoring unit I is used for measuring the voltage of the drain electrode of the Q1, and a voltage monitoring unit II is used for measuring the driving voltage of the grid electrode of the device. The invention further discloses an automatic sorting method. According to the invention, the conduction impedance is measured by adopting an isolation measurement method; the circuit structure is simple, and the monitoring voltage is always low; the forward conducting voltage drop of the diode is enabled to be consistent by adopting a double-diode back-to-back connection method; a specific ultra-small junction capacitor diode is adopted, so that the measuring frequency is the same as the actual working frequency and is in conformity with the fact.

Description

technical field [0001] The invention relates to an automatic sorting circuit and an automatic sorting method based on SiC MOSFET devices used in parallel. Background technique [0002] SiC MOSFET is a new generation of wide bandgap semiconductor device after silicon-based MOSFET, which has unparalleled superior performance of silicon-based. SiC material has wide bandgap, high breakdown electric field, high-speed carrier saturation drift velocity, excellent thermal stability and high thermal conductivity, so that SiC MOSFET can be prepared with high withstand voltage, high current, high temperature resistance, high Field effect transistors with superior performance such as high frequency and strong anti-interference. SiC MOSFET devices are still a developing field. In the future, they will surely lead the application of field effect transistors and continue the market law of the Moore effect. [0003] Compared with Si materials, the breakdown electric field of SiC MOSFET de...

AI Technical Summary

Problems solved by technology

This solution uses a self-matching solution, which sounds very good, but it only relies on better properties of the device and a slight improvement in improving efficiency, and it cannot actually eliminate the problem of current mismatch in the true sense.

It still depends on the characteristics of the device itself, just to reduce the possibility of mismatch as much as possible, and cannot fundamentally solve the problem

The third method is to connect positive temperature coefficient resistors (PTC) in parallel for compensation. This method itself has many defects. First, the temperature coefficient of on-resistance of each device must be measured, and then an appropriate PTC can be selected for compensation, and PTC The increase of will introduce additional loss, and it has not considered the switching loss, only for the conduction loss

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