Semiconductor device

A semiconductor device having a power source terminal, a ground terminal, a second ground terminal other than the ground terminal, an input terminal, an output terminal and a status output terminal, the semiconductor device comprising:

• a power semiconductor switch connected between the power source terminal and the output terminal;
• a logic circuit connected to the power semiconductor switch, the logic circuit being configured to generate, according to a signal inputted to the input terminal, an output logic signal for turning on or off the power semiconductor switch;
• and
• a ground terminal opening detection circuit connected to the ground terminal and the status output terminal, the ground terminal opening detection circuit being configured to detect a state in which the ground terminal is opened, based on a rise in a potential of the ground terminal, and to output, via the status output terminal, a detection signal in response to the detection of said state, wherein the ground terminal opening detection circuit includes:
• a pull-up circuit which is connected between the power source terminal and the ground terminal and which is configured to pull up the potential of the ground terminal;
• a first switching element configured to be turned on by the potential of the ground terminal pulled up by the pull-up circuit in the state in which the ground terminal is opened;
• a constant-current source connected between the power source terminal and the first switching element;
• a Zener diode connected in parallel with the first switching element;
• and
• a second switching element configured to be turned off in response to the first switching element being on, wherein
• the second switching element has a first terminal, at a high potential side thereof, connected to the status output terminal, and a second terminal, at a low potential side thereof, connected to the second ground terminal, and
• the Zener diode has an anode terminal thereof connected to the second ground terminal.

A semiconductor device having a power source terminal, a ground terminal, an input terminal, an output terminal and a status output terminal, the semiconductor device comprising:

• a power semiconductor switch connected between the power source terminal and the output terminal;
• a logic circuit connected to the power semiconductor switch, the logic circuit being configured to generate, according to a signal inputted to the input terminal, an output logic signal for turning on or off the power semiconductor switch;
• and
• a ground terminal opening detection circuit connected to the ground terminal and the status output terminal, the ground terminal opening detection circuit being configured to detect a state in which the ground terminal is opened, based on a rise in a potential of the ground terminal, and to output, via the status output terminal, a detection signal in response to the detection of said state, wherein the ground terminal opening detection circuit includes:
• a pull-up circuit which is connected between the power source terminal and the ground terminal and which is configured to pull up the potential of the ground terminal;
• a switching element configured to be turned on by the potential of the ground terminal pulled up by the pull-up circuit in the state in which the ground terminal is opened;
• a constant-current source connected between the power source terminal and the switching element;
• a Zener diode connected in parallel with the switching element;
• a reverse-current prevention diode having an anode terminal thereof connected to an anode terminal of the Zener diode;
• and
• a protection resistor having one terminal thereof connected to a cathode terminal of the reverse-current prevention diode, wherein
• the Zener diode has a cathode terminal thereof connected to the status output terminal, and
• the protection resistor has another terminal connected to the output terminal.

A semiconductor device having a power source terminal, a ground terminal, an input terminal, an output terminal, a first status output terminal and a second status output terminal, the semiconductor device comprising:

• a power semiconductor switch connected between the power source terminal and the output terminal, the power semiconductor switch being configured to supply power to a load via the output terminal;
• a load opening detection circuit connected to the output terminal, the load opening detection circuit being configured to detect a load opening based on a potential of the output terminal;
• a logic circuit connected to the power semiconductor switch and the first status output terminal, the logic circuit being configured to generate, according to a signal inputted to the input terminal, an output logic signal for turning on or off the power semiconductor switch, and to output, via the first status output terminal, a first detection signal in response to the detection of the load opening;
• a ground terminal opening detection circuit connected to the ground terminal and the second status output terminal, the ground terminal opening detection circuit being configured to detect a state in which the ground terminal is opened, based on a rise in a potential of the ground terminal, and to output, via the second status output terminal, a second detection signal in response to the detection of the ground terminal opening;
• and
• a controller configured to make a distinction between the load opening and the ground terminal opening based on levels of the first detection signal and the second detection signal.