Semiconductor drive device and power conversion apparatus

A power conversion apparatus, comprising:

• a switching element;
• a first current detection resistor and a second current detection resistor that are connected in series with each other for detecting a main current flowing through the switching element;
• and
• a semiconductor drive device configured to control a switching operation of the switching element based on a value of the main current detected by the first current detection resistor and the second current detection resistor,
• wherein the semiconductor drive device includes:
• a single-fault detection circuit configured to
• receive a first current detection voltage that appears at a connection point between the switching element and the first current detection resistor, and a second current detection voltage that appears at a connection point between the first current detection resistor and the second current detection resistor, and
• detect a short-circuit state of the first current detection resistor or the second current detection resistor;
• and
• a control circuit including
• a comparator configured to determine a switching control timing of the switching element by comparing the first current detection voltage with a first threshold voltage or a second threshold voltage, and
• a threshold voltage switching circuit configured to output the first threshold voltage while the single-fault detection circuit detects neither the short-circuit state of the first current detection resistor nor the short-circuit state of the second current detection resistor, and to output the second threshold voltage, which is less than the first threshold voltage, upon the single-fault detection circuit detecting either the short-circuit state of the first current detection resistor or the short-circuit state of the second current detection resistor.