SEMICONDUCTOR DEVICE

To detect the voltage abnormality between a positive electrode and a negative electrode when a semiconductor switching element is on while the circuit scale is suppressed without the increase in consumption power.SOLUTION: When an on period for a high breakdown voltage switch 120 is provided in an on period for a semiconductor switching element 10a, a detection circuit 110 outputs a voltage, which results from dividing of a terminal-terminal voltage Vce with resistors R1 and R2, to a node N1. A voltage comparison circuit 130 outputs a detection signal Sab expressing whether the terminal-terminal voltage Vce is higher than predetermined judging voltage on the basis of the comparison between the voltage at the node N1 and DC voltage Vt. The high breakdown voltage switch 120 has the breakdown voltage for blocking the potential difference between a high potential VDD and a low potential GND in an off period.SELECTED DRAWING: Figure 1 【課題】消費電力の増大を招くことなく、かつ、回路規模を抑制した、半導体スイッチング素子のオン時における正電極及び負電極間の電圧異常検出を検出する。【解決手段】半導体スイッチング素子１０ａのオン期間に高耐圧スイッチ１２０のオン期間が設けられると、検出回路１１０は、端子間電圧Ｖｃｅを抵抗素子Ｒ１，Ｒ２で分圧した電圧をノードＮ１に出力する。電圧比較回路１３０は、ノードＮ１の電圧と、直流電圧Ｖｔとの比較に基づき、端子間電圧Ｖｃｅが予め定められた判定電圧より大きいか否かを示す検出信号Ｓａｂを出力する。高耐圧スイッチ１２０は、オフ期間において、高電位ＶＤＤ及び低電位ＧＮＤの電位差を遮断する耐圧を有する。【選択図】図１