DRIVE CIRCUIT FOR SEMICONDUCTOR SWITCHING ELEMENT AND SEMICONDUCTOR SWITCHING ELEMENT MODULE HAVING THE SAME

摘要

In a drive circuit, a threshold voltage control device is activated when a mode determination circuit determines a specific mode switching signal. The threshold voltage control device controls a threshold voltage of a comparator through a threshold voltage setting device to be sequentially changed in a period where a semiconductor switching element is turned on in a state where a constant current is externally supplied between conduction terminals of the semiconductor switching element. The threshold voltage control device stores data corresponding to the threshold voltage of a time point where an output signal of the comparator changes due to the threshold voltage being changed to a nonvolatile storage. The threshold voltage control device reads out the threshold voltage from the storage and permits the threshold voltage setting device to set the threshold voltage read out to the comparator, when the mode determination circuit determines a drive control signal.

主权项

1. A drive circuit for providing a drive signal to a conduction control terminal of a semiconductor switching element according to a drive control signal received from an external device through an input terminal, the drive circuit comprising:
a comparator comparing a voltage converted according to a current generated when the semiconductor switching element is turned on with a threshold voltage, and outputting an overcurrent detection signal; a threshold voltage setting device variably setting the threshold voltage; a nonvolatile storage storing data corresponding to the threshold voltage; a mode determination circuit determining whether an input signal received from the external device through the input terminal is the drive control signal or a specific mode switching signal; and a threshold voltage control device:
being activated when the mode determination circuit determines that the input signal is the specific mode switching signal;controlling the threshold voltage through the threshold voltage setting device to be sequentially changed in a period where the semiconductor switching element is turned on in a state where a constant current is externally supplied between conduction terminals of the semiconductor switching element;storing data corresponding to the threshold voltage of a time point where an output signal of the comparator changes due to the threshold voltage being changed in the storage; andreading out the threshold voltage based on the data stored in the storage and permitting the threshold voltage setting device to set the threshold voltage read out to the comparator, when the mode determination circuit determines that the input signal is the drive control signal.