Overcurrent protection device for semiconductor element

摘要

An overcurrent protecting device for protecting a semiconductor element (1) from an overcurrent includes: the semiconductor element (1); a shunt resistor (9) for detecting the overcurrent when the electric current in the semiconductor element (1) exceeds a threshold value; a reference resistor (13) for setting the threshold value; a constant electric current circuit (12) for supplying a constant electric current to the reference resistor (13); and a comparator (10) for comparing a terminal voltage of the shunt resistor (9) and a terminal voltage of the reference resistor (13). The shunt resistor (9) is made of a same kind of resistor as the reference resistor (13).