Patent ID: 8253398

Claim:
A semiconductor device comprising: a high-side switching element having a first switching element connected between an input voltage line and an inductive load; and a low-side switching element having a second switching element and a third switching element that are connected in parallel between the inductive load and a reference voltage line, a surge current being discharged through the third switching element to the reference voltage line when a surge is applied to a terminal connected to the inductive load in the low-side switching element, wherein the low-side switching element comprises, a semiconductor layer of a first conductivity type, a source layer of a second conductivity type provided on a portion of the semiconductor layer, a drain layer of the second conductivity type provided so as to be separate from the source layer on a portion of the semiconductor layer, a drift layer of the second conductivity type provided to contact the drain layer between the source layer and the drain layer and having lower impurity concentration than that of the drain layer, a first main electrode connected to the drain layer, a second main electrode connected to the source layer, and a gate electrode provided through an insulating film on a surface of the semiconductor layer between the source layer and the drift layer, and L1>L2 being satisfied, where L1 is a length of the drift layer in the second switching element and L2 is a length of the drift layer in the third switching element, and the third switching element has lower breakdown voltage than that of the second switching element.