Silicon carbide MOSFET short circuit protection circuit

Abstract

The invention discloses a silicon carbide MOSFET short-circuit protection circuit which comprises a silicon carbide MOSFET driving module, a silicon carbide MOSFET conduction voltage detection module, a partial voltage sampling module, a reference level module and a comparison output module. The silicon carbide MOSFET driving module comprises a silicon carbide driving board, a main control board and a first resistor; the silicon carbide MOSFET conduction voltage detection module comprises a first diode, a second diode and a second resistor; the voltage division sampling module comprises a third resistor, a fourth resistor, a fifth resistor, a voltage stabilizing diode, a third diode and a capacitor; the reference level module comprises a voltage reference chip, a sixth resistor, a seventh resistor and an eighth resistor; the comparison output module comprises a voltage comparator and a ninth resistor. According to the invention, the short circuit can be quickly identified under the high switching frequency of the silicon carbide MOSFET, the negative voltage reference is adapted, the cost is low, the reliability is high, and the market promotion is facilitated.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a silicon carbide MOSFET short-circuit protection circuit. Background technique [0002] With the rapid development of the third-generation semiconductor technology, more and more third-generation semiconductor devices are applied to power electronic equipment. Silicon carbide (SIC) MOSFET, as an important representative of the third-generation semiconductor, has been widely used in the fields of industry, automobiles, and national defense for its high operating temperature, high blocking voltage, and good high-frequency characteristics. [0003] For the short-circuit protection circuit of silicon carbide MOSFET, the most commonly used method is to improve the short-circuit protection circuit of silicon devices or IGBTs. This type of short-circuit protection circuit is either integrated in the drive module or implemented by using more complex amplification and compariso...

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Problems solved by technology

[0003] For the short-circuit protection circuit of silicon carbide MOSFET, the most commonly used method is to improve the short-circuit protection circuit of silicon devices or IGBTs. This type of short-circuit protection circuit is either integrated in the drive module or implemented by using more complex amplification and comparison logic. The cost is relatively expensive; moreover, when silicon devices and IGBTs are used in electronic equipment, the switching frequency is usually below 20KHz, while the switching frequency of silicon carbide MOSFET is usually above 100KHz, which means that this type of short circuit protection circuit in When a short circuit occurs, it is necessary to identify and respond in a shorter time; in addition, the driving circuit of a silicon device is usually turned on with a positive voltage and turned off at zero level, while a silicon carbide MOSFET needs to be turned on with a positive voltage and turned off with a negative voltage. The voltage reference of similar short-circuit protection circuits is usually based on zero level. If a negative voltage is used as a reference, it is difficult to apply

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