Power semiconductor device

A power semiconductor device comprising:

• a package;
• a first fixed-potential terminal attached to the package and externally connectable outside the package;
• a voltage output terminal attached to the package and externally connectable outside the package;
• a first semiconductor switching element housed in the package and connected between the first fixed-potential terminal and the voltage output terminal;
• a first driving circuit housed in the package and driving the first semiconductor switching element;
• a second fixed-potential terminal attached to the package and externally connectable outside the package;
• a second semiconductor switching element housed in the package and including a first element terminal connected to the voltage output terminal, a second element terminal connected to the second fixed-potential terminal, an element control terminal that accepts a driving signal for controlling a current path between the first element terminal and the second element terminal to either an ON state or an OFF state, and a sense terminal in which a current proportionate to a current flowing through the current path and lower than the current flowing through the current path flows;
• an external control terminal attached to the package and externally connectable outside the package;
• an external detection terminal for accepting a voltage signal proportionate to magnitude of a current in the second fixed-potential terminal;
• and
• a second driving circuit housed in the package, the second driving circuit including:
• a first comparator circuit that determines whether magnitude of the current in the second fixed-potential terminal indicated by the voltage signal from the external detection terminal is within a permissible range or beyond the permissible range;
• an internal detection terminal electrically connected to the sense terminal of the second semiconductor switching element in the package for detecting magnitude of a current in the sense terminal;
• a second comparator circuit that determines whether magnitude of the current in the sense terminal detected by using the internal detection terminal is within a permissible range or beyond the permissible range;
• and
• a driving signal generator that selectively generates either an ON signal for placing the second semiconductor switching element in an ON state or an OFF signal for placing the second semiconductor switching element in an OFF state as the driving signal in response to a signal from the external control terminal, the driving signal generator being prohibited from generating the ON signal as the driving signal if at least one of the first comparator circuit and the second comparator circuit determines that current magnitude is beyond the permissible range.