Charge/discharge control circuit and battery device
View Patent ↗The level shifter circuit includes: a first transistor including a gate connected to an input terminal of the level shifter circuit and a source connected to a first power supply terminal; a first resistor including one terminal connected to the input terminal of the level shifter circuit; a second transistor including a gate connected to another terminal of the first resistor, a drain connected to a drain of the first transistor, and a source connected to a terminal for inputting the voltage subjected to the level conversion; and a third transistor including a gate and a drain connected to the another terminal of the first resistor, and a source connected to the terminal for inputting the voltage subjected to the level conversion. Further, the battery device includes the charge/discharge control circuit.
1. A charge/discharge control circuit for controlling charge and discharge of a secondary battery to be connected between a first terminal and a second terminal,
wherein the charge/discharge control circuit comprises:
a control circuit, connected between the first terminal and the second terminal, for monitoring a voltage of the secondary battery;
a level shifter circuit for level-converting a voltage of a charge control signal output from the control circuit; and
a third terminal for inputting the voltage subjected to the level-converting, and
wherein the level shifter circuit comprises:
a first transistor of a first conductivity type, including a gate connected to an input terminal of the level shifter circuit and a source connected to the first terminal;
a first resistor including one terminal connected to the input terminal of the level shifter circuit;
a second transistor of a second conductivity type, including a gate connected to another terminal of the first resistor, a drain connected to a drain of the first transistor, and a source connected to the third terminal; and
a third transistor of the second conductivity type, including a gate and a drain connected to said another terminal of the first resistor, and a source connected to the third terminal.
2. A charge/discharge control circuit according to claim 1 , wherein the level shifter circuit further comprises:
a Zener diode including an anode connected to the drain of the first transistor and a cathode connected to the first terminal; and
a second resistor connected between the drain of the first transistor and the drain of the second transistor.
3. A charge/discharge control circuit according to claim 1 , wherein the level shifter circuit further comprises:
a diode including a cathode connected to the drain of the first transistor and an anode connected to the second terminal; and
a second resistor connected between the drain of the first transistor and the drain of the second transistor.
4. A battery device, comprising:
a chargeable/dischargeable secondary battery;
a charge/discharge control switch provided in a charge/discharge path of the chargeable/dischargeable secondary battery; and
the charge/discharge control circuit according to claim 1 , for monitoring a voltage of the chargeable/dischargeable secondary battery and controlling charge and discharge of the chargeable/dischargeable secondary battery by turning on and off the charge/discharge control switch.