Switch circuit, semiconductor device, and battery device
View Patent ↗There is provided a semiconductor device capable of preventing the passage of current that is unexpected in a circuit operation even in the case of reverse connection, thus ensuring higher safety. The semiconductor device has a switch circuit which includes: a first transistor; a second transistor having a drain thereof connected to a drain of the first transistor, a source and a back gate thereof connected to a back gate of the first transistor, and a gate thereof connected to a source of the first transistor; and a third transistor having a drain thereof connected to the source of the first transistor, a source and a back gate thereof connected to the back gate of the first transistor, and a gate thereof connected to the drain of the first transistor.
1. A switch circuit comprising:
a first transistor;
a second transistor having a drain thereof connected to a drain of the first transistor, a source and a back gate thereof connected to a back gate of the first transistor, and a gate thereof connected to a source of the first transistor; and
a third transistor having a drain thereof connected to the source of the first transistor, a source and a back gate thereof connected to the back gate of the first transistor, and a gate thereof connected to the drain of the first transistor.
2. A semiconductor device comprising:
a voltage control circuit having a control circuit which detects a voltage applied between a first voltage monitoring terminal and a second voltage monitoring terminal, and
the switch circuit according to claim 1 , in which the gate of the first transistor is connected to an output terminal of the control circuit, the drain thereof is connected to the first voltage monitoring terminal, and the source thereof is connected to the second voltage monitoring terminal.
3. A battery device comprising:
a plurality of secondary batteries connected in series;
a charge/discharge control switch provided on a charge/discharge path of the plurality of secondary batteries;
a charge/discharge control circuit which monitors the voltages of the plurality of secondary batteries and controls the charge/discharge of the secondary batteries by opening/closing the charge/discharge control switch; and
the semiconductor device according to claim 2 , which is connected in parallel to each of the plurality of secondary batteries and which controls the voltages of the plurality of secondary batteries.
4. A semiconductor device comprising:
a voltage detector circuit having a control circuit which detects a voltage applied between a first voltage monitoring terminal and a second voltage monitoring terminal, and
the switch circuit according to claim 1 , in which the gate of the first transistor is connected to an output terminal of the control circuit, the drain thereof is connected to the first voltage monitoring terminal through a resistor, and the source thereof is connected to the second voltage monitoring terminal.