Ablic Inc.

Sii Semiconductor Corporation

Seiko Instruments Inc

Fumihiko Maetani

Toshiyuki Koike

Atsushi Sakurai

Kazuaki Sano

Takashi Ono

Satoshi Abe

Hiroshi Saito

Masakazu Sugiura

Akihiko Suzuki

Shohei Tsukamoto

Takahiro Kuratomi

Wataru Sakamoto

Takashi Matsuda

The charge control circuit includes a cell connection detection circuit monitoring a voltage between input ports to which terminals of a cell pack are connected, an overvoltage detection circuit monitoring an overvoltage of the secondary cells, a first latch circuit receiving a signal output by the cell connection detection circuit, a second latch circuit receiving a signal output by the overvoltage detection circuit, a reset circuit outputting a signal to the first latch circuit and the second latch circuit when the charge control circuit is activated, and a control circuit receiving a signal output from the second latch circuit and outputting a signal for protecting the cell pack from the overvoltage. The control circuit does not output a signal for blowing the fuse until the first latch circuit receives a detection signal of the cell connection detection circuit.

Charge control circuit, charge control device, and battery device

There is provided a reference voltage circuit which includes a depletion type transistor and an enhancement type transistor. At least one of the depletion type transistor and the enhancement type transistor is formed from a plurality of transistors and the reference voltage circuit is arranged in the form of a common centroid (common center of mass) to avoid the influence of a characteristic fluctuation due to stress from the resin encapsulation of a semiconductor device or the like.

Reference voltage circuit including depletion type and enhancement type transistors in a common centroid arrangement

A charge-discharge control circuit includes a positive power-supply terminal; a negative power-supply terminal; a charge-discharge discrimination circuit which discriminates a discharging state in which a discharging current flows and a charging state in which a charging current flows based on a voltage at a charge-discharge path and a preset charge-discharge discrimination voltage; and a control circuit which turns on a discharge control FET and a charge control FET in a charge-inhibition state and the discharging state or turns off the charge control FET in the charge-inhibition state and the charging state.

Charge-discharge control circuit, charge-discharge control device, and battery device

Provided is a charge/discharge control circuit for controlling charging and discharging of a secondary cell. The charge/discharge control circuit includes a positive power supply terminal and a negative power supply terminal configured to monitor a voltage of the secondary cell, a charge control signal output terminal from which a charge control signal is output, the charge control signal controlling stopping and allowing charging of the secondary cell, a discharge control signal output terminal, an overcurrent detection terminal, an overcurrent cancel terminal, an external voltage input terminal provided separately from the overcurrent cancel terminal, a discharge overcurrent detection circuit connected to the overcurrent detection terminal, to which a discharge overcurrent detection voltage is set, and a discharge overcurrent cancel circuit connected to the overcurrent cancel terminal, to which a discharge overcurrent cancel voltage is set.

Charge/discharge control circuit and battery device including the same

A charge/discharge control circuit includes: a first power supply terminal connected to a first electrode of a secondary battery; a second power supply terminal connected to a second electrode of the secondary battery; a control circuit configured to control charge/discharge of the secondary battery; and a power-down release pulse generation circuit connected to the power-down release terminal, the power-down release pulse generation circuit being configured to supply, in a power-down state of the charge/discharge control circuit, a power-down release pulse at least to the control circuit in response to an input of a power-down release signal to the power-down release terminal to release the power-down state.

Charge/discharge control circuit and battery device

A charge/discharge control device and a battery apparatus respectively include a discharging-overcurrent-detection circuit which monitors a discharging overcurrent according to a discharging-overcurrent-reference voltage based on the voltage of a discharging-overcurrent-detection terminal, and the voltage of a discharge-reference FET having a drain and a gate connected to those of a charge control FET.

Charge/discharge control device and battery apparatus

A charge/discharge control circuit includes: a first power supply terminal connected to a first electrode of a secondary battery; a second power supply terminal connected to a second electrode of the secondary battery; a charge control terminal connected to a discharge control switch and a charge control switch; a detection terminal; a control circuit; and an output circuit configured to output a charge control signal from the charge control terminal, and configured to output a first voltage when a charger is connected and the control circuit permits charging, and to output a voltage of the detection terminal which differs from the first voltage when the charger is connected and the control circuit prohibits charging. The output circuit is capable of outputting a voltage of the second power supply terminal which differs from the first voltage when the charger is not connected.

There is provided a constant current circuit having a current characteristic satisfactory in a high voltage circuit while being low in manufacturing cost. The constant current circuit includes a high breakdown-voltage depletion type NMOS transistor and a low breakdown-voltage depletion type NMOS transistor connected in series between a first terminal and a second terminal. The low breakdown-voltage depletion type NMOS transistor includes a first depletion type NMOS transistor and a second depletion type NMOS transistor connected in series. The high breakdown-voltage depletion type NMOS transistor has a gate connected to a connecting point of the first depletion type NMOS transistor and the second depletion type NMOS transistor.

Constant current circuit

Provided is a battery device high in safety and ease of use, which has no difficulty in returning to a normal state after discharge overcurrent is detected. The battery device includes a first charge/discharge control device including a first charge/discharge control transistor, and a first charge/discharge control circuit configured to detect the voltage of a secondary battery to control charging and discharging; a second charge/discharge control device including a second charge/discharge control transistor connected to an external terminal via the first charge/discharge control transistor, and a second charge/discharge control circuit configured to detect the voltage of the secondary battery to control charging and discharging; and a switch circuit arranged between an overcurrent detection terminal of the second charge/discharge control circuit and the external terminal. The switch circuit is turned on with a discharge stopping signal of the second charge/discharge control circuit.

Battery device

Provided is a battery device having high overcurrent detection current accuracy that suppresses increases in a resistance value of a charge/discharge path and in a manufacturing cost. A first charge/discharge control device is configured to monitor a charge/discharge current with a voltage generated across both ends of a charge/discharge control switch, and a second charge/discharge control device is configured to monitor the charge/discharge current with a voltage generated across both ends of a current sensing resistor. A field effect transistor forming the charge/discharge control switch is selected based on a desired ON resistance value. The charge/discharge control switch of the first charge/discharge control device includes a field effect transistor having the desired ON resistance value, and a charge/discharge control switch of the second charge/discharge control device includes a field effect transistor having an ON resistance value other than the desired ON resistance value.

There is provided a battery device in which the accuracy of an over-current detection current value is high to have high safety. In a charging/discharging control circuit, a reference voltage circuit of an over-current detection circuit is configured to include a constant current circuit, a resistor, and a transistor having a resistance value that varies with a voltage of a secondary cell, that are connected to both ends of the secondary cell, and outputs, as a reference voltage, a voltage that is generated due to the flowing of a current of the constant current circuit to the resistor and the transistor.

Charging/discharging control circuit, charging/discharging control device, and battery device

Provided is a highly safe battery device in which the accuracy of an overcurrent detection current value and a short-circuit current value is improved and current consumption is reduced. A short-circuit and overcurrent detecting circuit includes: a reference voltage circuit configured to output a reference voltage generated when a constant current flows through an impedance element and a transistor having a resistance value that is changed depending on a voltage of a secondary battery; a first comparator circuit configured to compare a voltage of an overcurrent detecting terminal with the reference voltage; and a second comparator circuit configured to compare a voltage based on the voltage of the overcurrent detecting terminal with the reference voltage.

Charge and discharge control circuit and battery device

A short-circuit and overcurrent detecting circuit includes a reference voltage circuit including a constant current circuit, a first impedance element, a first transistor having a resistance value depending a voltage of a secondary battery, a second impedance element, and a second transistor having a resistance value depending the voltage of the secondary battery, which are connected in series. The reference voltage circuit outputs a first reference voltage from a node of the constant current circuit and the first impedance element, and outputs a second reference voltage from a node of the first transistor and the second impedance element. The short-circuit and overcurrent detecting circuit further includes: a first comparator circuit for comparing a voltage of an overcurrent detecting terminal with the first reference voltage; and a second comparator circuit for comparing the voltage of the overcurrent detecting terminal with the second reference voltage.

Provided is a highly safe battery device in which the accuracy of an overcurrent detection current value is high. A charge and discharge control circuit includes an overcurrent detecting terminal, an overcurrent detecting circuit for detecting overcurrent of a secondary battery, the overcurrent detecting circuit being connected to the overcurrent detecting terminal, and a constant current circuit for causing a current to flow to the overcurrent detecting terminal.

Charge and discharge control circuit, charge and discharge control unit, and battery device

Provided is a battery device with high convenience, which is capable of setting overcurrent release impedance to be low. The battery device includes: a first comparator circuit for detecting an overcurrent based on a first reference voltage; and a second comparator circuit for outputting an overcurrent release voltage control signal based on a second reference voltage that is higher than the first reference voltage.

Growing community of inventors

Chiba, Japan

Fumihiko Maetani