Driving circuit for power semiconductor element

Abstract

When it is applied to the IGBT1 with high withstand voltage, it is necessary to connect the diodes 5 with high withstand voltage in series in multiple stages, and there is a problem of high cost or reduced reliability. In addition, the collector voltage detection circuit 6 performs Short-circuit detection lags significantly, and there is a problem that sometimes the IGBT1 cannot be protected. The solution is that the sampling circuit 16 detects the gate voltage Vge during the detection processing period of the allowable gate voltage Vge, and if the gate voltage Vge exceeds the reference value, It is determined that an abnormality has occurred in the IGBT11.

Description

technical field [0001] The present invention relates to a driving circuit of a power semiconductor element for detecting an abnormality occurring in the power semiconductor element. Background technique [0002] Figure 24 It is a structural diagram showing a drive circuit of a conventional power semiconductor element. In the figure, 1 is an IGBT (Insulated Gate Bipolar Transistor) as a power semiconductor element, and 2 is a switch to switch IGBT1 when a conduction command is input from the outside. The gate command to the closed state is output to the buffer 3, and if the shut-off command is input from the outside, the gate command to transfer the IGBT1 to the open state is output to the control logic block of the buffer 3, and 3 is based on the slave control logic The gate command output by block 2 drives the buffer of IGBT1, 4a is the turn-on gate resistance, 4b is the turn-off gate resistance, 5 is the cathode connected to the collector of IGBT1, and the anode is connec...

AI Technical Summary

Problems solved by technology

For this reason, the short-circuit detection by the collector voltage detection circuit 6 is significantly delayed, and there is a problem that the IGBT1 may not be protected.

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