PROTECTION CIRCUIT FOR WITHSTANDING SHORT-CIRCUIT OF INSULATED GATE TYPE POWER DEVICE, CAPABLE OF PREVENTING BREAKDOWN OF POWER DEVICE CAUSED DUE TO HIGH VOLTAGE OF POWER SOURCE UNIT UPON OCCURRENCE OF SHORT-CIRCUIT OF LOAD

摘要

PURPOSE: A protection circuit is provided to prevent breakdown of a power device caused due to the high voltage of a power source unit upon occurrence of short-circuit of a load. CONSTITUTION: A protection circuit(200) comprises a pass transistor(210), a pull-down unit(220), and a reset diode(230). The pass transistor has a gate connected to a gate of an insulated gate type power device at a gate A, and transfers an anode voltage to a node B. The pull-down unit is connected between a gate electrode terminal of the insulated gate type power device and the node B, and pulls down the voltage of the node A when the voltage at the node B is higher than a threshold voltage. The reset diode lowers the voltage of the node B to zero when the voltage of the gate electrode terminal is zero.