Semiconductor drive device and power conversion device comprising same

A semiconductor drive device comprising:

• a gate drive circuitry which applies voltage to a control terminal of a semiconductor switching element, to perform ON/OFF driving of the semiconductor switching element;
• and
• an overcurrent protection circuitry including an overcurrent determination circuitry which receives a detection signal based on voltage/current between main terminals of the semiconductor switching element and determines whether there is overcurrent flowing through the semiconductor switching element, and a gate voltage reducing circuitry which reduces voltage applied to the control terminal when it is determined that there is the overcurrent, thus protecting the semiconductor switching element, wherein
• the overcurrent determination circuitry includes
• a clamp diode for clamping a potential of a signal input part where the detection signal is inputted, at a potential of the control terminal,
• a first transistor to which the signal input part is connected, and
• a low-pass filter provided at the signal input part, and
• when the potential of the signal input part has reached a set value, the first transistor is turned on, so that the overcurrent determination circuitry determines that there is the overcurrent in the semiconductor switching element.