Short circuit protection circuit and method of silicon carbide device

Abstract

The invention discloses a short circuit protection circuit and method of a silicon carbide device. The method comprises steps of: detecting a first real-time gate voltage of the silicon carbide devicein running; if the first real-time gate voltage is greater than a first voltage threshold, outputting a first fault signal; detecting a second real-time gate voltage of the silicon carbide device inrunning; if the second real-time gate voltage is greater than a second voltage threshold, outputting a second fault signal; and if the first fault signal and the second fault signal are detected consecutively, determining that short circuit occurs in the silicon carbide device. The circuit comprises a drive signal control unit, a first controller, a comparator, a logic processing unit, a second signal isolation unit and a voltage threshold control unit. The short circuit protection circuit responds rapidly, has high universality and is lower in cost.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices, in particular to a short circuit protection circuit and method for a silicon carbide device. Background technique [0002] With the continuous improvement of semiconductor process technology, the performance of Si (silicon) devices has approached the theoretical limit of the material itself, making the growth of power density appear a saturation trend, and its development speed can no longer meet the high-performance requirements of the market. With the rapid development of wide bandgap semiconductor material preparation, manufacturing process and device physics represented by SiC (silicon carbide), SiC power electronic devices have gradually become an important development target of power semiconductor devices. [0003] Due to the poor over-current capability of SiC, the subsequent technical difficulty is the short-circuit protection method of SiC devices. It is necessary to ensure...

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Problems solved by technology

[0004] Detection is performed through series resistors or series diodes; the series resistance detection method is mainly used for short-circuit protection of Si devices, and also has certain applications in the SiC field. However, due to the short-circuit protection time required by SiC, the required RC value in the detection circuit is low. , when the whole machine is running, it is easy to be interfered and lead to false alarm failure, which affects the reliable operation of the system;

[0005] Through mirror current detection; some SiC devices on the market have a mirror current detection terminal in the module for overcurrent detection and protection of the device to prevent overcurrent damage to the device, but due to the additional detection terminal, the requirements for the device process increase, and Different from the traditional packaging, the driver design needs to re-match different detection circuits, which increases the complexity and poor versatility

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