Abstract: A secondary battery protection integrated circuit includes a first power supply terminal, a second power supply terminal, an input terminal, an output terminal, and a control circuit. The control circuit turns a discharge control transistor off to change to a discharge-blocked state in which the output terminal and the first power supply terminal are coupled to each other, upon occurrence in a condition in which a potential level of the input terminal changes from a first level. The control circuit turns the discharge control transistor on in the discharge blocked state, upon occurrence of a condition in which the input terminal changes from a second level that is different from the first level.

Abstract: A secondary battery protection apparatus includes a temperature sensitive element having a characteristic value that varies in accordance with a change in temperature of a secondary battery. The secondary battery protection apparatus includes a switching circuit provided in a charge-and-discharge path between a secondary battery and an external device. The secondary battery protection apparatus includes a secondary battery protection circuit configured to control charge and discharge using the switching circuit to protect the secondary battery from temperature. The secondary battery protection circuit includes a comparison circuit configured to compare a voltage against a threshold voltage, the voltage corresponding to the change in the temperature of the secondary battery. The secondary battery protection circuit includes a conversion circuit that is controlled such that a first input of the comparison circuit is electrically coupled to a first terminal of the secondary battery protection circuit.

Abstract: A secondary battery protection circuit for controlling charge and discharge using a switching circuit to protect a secondary battery from temperature is provided. The switching circuit is configured to be provided in a charge-and-discharge path between the secondary battery and an external device. The secondary battery protection circuit includes a detection terminal configured to be electrically connected, via a resistor, to between the switching circuit and the external device. The secondary battery protection circuit includes a first terminal configured to be electrically connected to a temperature detection terminal of the external device. The secondary battery protection circuit includes a second terminal to which a temperature sensitive element is configured to be electrically connected, the temperature sensitive element having a characteristic value varying in accordance with a change in temperature of the secondary battery.

Abstract: A secondary-battery protection circuit is configured to, in response to detecting that a first switching circuit is turned on and a second switching circuit is turned on, supply a first output voltage to a first load between a first terminal and a second terminal; and supply a third output voltage to a second load between the first terminal and a third terminal, the third output voltage indicating the sum of the first output voltage and a second output voltage, the second output voltage corresponding to a voltage across a second secondary battery. In response to detecting that the first switching circuit is turned off and the second switching circuit is turned on, the secondary-battery protection circuit is configured to stop supplying the first output voltage to the first load; and stop supplying the third output voltage via the first terminal and the third terminal.

Abstract: A secondary-battery protection circuit is configured to, in response to detecting that a first switching circuit is turned on and a second switching circuit is turned on, supply a first output voltage to a first load between a first terminal and a second terminal; and supply a third output voltage to a second load between the first terminal and a third terminal, the third output voltage indicating the sum of the first output voltage and a second output voltage, the second output voltage corresponding to a voltage across a second secondary battery. In response to detecting that the first switching circuit is turned off and the second switching circuit is turned on, the secondary-battery protection circuit is configured to stop supplying the first output voltage to the first load; and stop supplying the third output voltage via the first terminal and the third terminal.

Abstract: A secondary-battery protection circuit is configured to, in response to detecting that a first switching circuit is turned on and a second switching circuit is turned on, supply a first output voltage to a first load between a first terminal and a second terminal; and supply a third output voltage to a second load between the first terminal and a third terminal, the third output voltage indicating the sum of the first output voltage and a second output voltage, the second output voltage corresponding to a voltage across a second secondary battery. In response to detecting that the first switching circuit is turned off and the second switching circuit is turned on, the secondary-battery protection circuit is configured to stop supplying the first output voltage to the first load; and stop supplying the third output voltage via the first terminal and the third terminal.

Abstract: A secondary battery protection circuit for controlling charge and discharge using a switching circuit to protect a secondary battery from temperature is provided. The switching circuit is configured to be provided in a charge-and-discharge path between the secondary battery and an external device. The secondary battery protection circuit includes a detection terminal configured to be electrically connected, via a resistor, to between the switching circuit and the external device. The secondary battery protection circuit includes a first terminal configured to be electrically connected to a temperature detection terminal of the external device. The secondary battery protection circuit includes a second terminal to which a temperature sensitive element is configured to be electrically connected, the temperature sensitive element having a characteristic value varying in accordance with a change in temperature of the secondary battery.

Abstract: A secondary-battery protection circuit is configured to, in response to detecting that a first switching circuit is turned on and a second switching circuit is turned on, supply a first output voltage to a first load between a first terminal and a second terminal; and supply a third output voltage to a second load between the first terminal and a third terminal, the third output voltage indicating the sum of the first output voltage and a second output voltage, the second output voltage corresponding to a voltage across a second secondary battery. In response to detecting that the first switching circuit is turned off and the second switching circuit is turned on, the secondary-battery protection circuit is configured to stop supplying the first output voltage to the first load; and stop supplying the third output voltage via the first terminal and the third terminal.

Abstract: A battery protection circuit for protecting a secondary battery, the battery protection circuit not having a CPU, includes a non-volatile memory into which characteristics data determining protective characteristics of the battery protection circuit are writable; and a protection operation circuit which performs a protection operation of the secondary battery based on the characteristics data read out of the non-volatile memory.

Abstract: A secondary protection IC is connected in parallel with a rechargeable battery and controls the charge and discharge of the rechargeable battery separately from a primary protection IC. The secondary protection IC includes a detection circuit that detects an overcharge or overdischarge of the rechargeable battery, a regulator that stabilizes the voltage of the rechargeable battery and outputs the stabilized voltage to the outside of the rechargeable battery, and a control terminal that controls the regulator with a control signal. Each of the detection circuit and the regulator performs a normal operation or stops operating based on the voltage of the rechargeable battery and the control signal.

Abstract: In a battery pack, an overcharge detecting circuit compares a voltage between a positive electrode and a negative electrode of a secondary battery with a threshold voltage to detect an overcharge of the secondary battery, and turns off a switching element. A series circuit including a thermistor and a resistor is arranged near the secondary battery and connected in parallel to the secondary battery. A comparator compares a voltage at a junction point of the thermistor and the resistor with a reference voltage corresponding to a predetermined temperature. In response to an output signal of the comparator, a changing unit changes the threshold voltage to a first value when a temperature of the secondary battery is below the predetermined temperature, and changes the threshold voltage to a second smaller value when the temperature of the secondary battery is above the predetermined temperature.

Abstract: A battery protection circuit for protecting a secondary battery, the battery protection circuit not having a CPU, includes a non-volatile memory into which characteristics data determining protective characteristics of the battery protection circuit are writable; and a protection operation circuit which performs a protection operation of the secondary battery based on the characteristics data read out of the non-volatile memory.

Abstract: A charge controller includes a charge control circuit that, when detecting that a charging power supply is connected, controls the charging transistor to apply the charge current; a first and second control switch element connected in series between one terminal of a secondary battery and an external terminal; and a protection circuit that, when the secondary battery is over-discharged, turns off the first control switch element to stop discharge current and when deeply discharged, turns off the second control switch element. The protection circuit sends a charge inhibit signal to the charge control circuit when the secondary battery is deeply discharged, and while receiving the charge inhibit signal, the charge control circuit keeps the charging transistor off to prevent the charge current from flowing even if detecting that the charging power supply is connected.

Abstract: A charge controller includes a charge control circuit which controls a charging transistor; and a protection circuit that, when the secondary battery is over-discharged, turns off the first control switch element to block discharge current and when the secondary battery is overcharged, turns off the second control switch element to prevent the charge current from flowing. The charge control circuit includes a function of control for applying constant charge current through the charging transistor until the voltage of the secondary battery reaches a predetermined value and switching to control for applying charge current at a constant voltage after the voltage of the secondary battery reaches the predetermined value, and a terminal voltage on the positive electrode side and a terminal voltage on the negative electrode side of the secondary battery are supplied as monitoring voltage to the charge control circuit.

Abstract: A charge controller includes a charge control circuit that, when detecting that a charging power supply is connected, controls the charging transistor to apply the charge current; a first and second control switch element connected in series between one terminal of a secondary battery and an external terminal; and a protection circuit that, when the secondary battery is over-discharged, turns off the first control switch element to stop discharge current and when deeply discharged, turns off the second control switch element. The protection circuit sends a charge inhibit signal to the charge control circuit when the secondary battery is deeply discharged, and while receiving the charge inhibit signal, the charge control circuit keeps the charging transistor off to prevent the charge current from flowing even if detecting that the charging power supply is connected.

Abstract: A secondary protection IC is connected in parallel with a rechargeable battery and controls the charge and discharge of the rechargeable battery separately from a primary protection IC. The secondary protection IC includes a detection circuit that detects an overcharge or overdischarge of the rechargeable battery, a regulator that stabilizes the voltage of the rechargeable battery and outputs the stabilized voltage to the outside of the rechargeable battery, and a control terminal that controls the regulator with a control signal. Each of the detection circuit and the regulator performs a normal operation or stops operating based on the voltage of the rechargeable battery and the control signal.

Abstract: A charge/discharge control circuit for controlling charging and discharging of multiple secondary batteries includes a series-connection switch part that connects the multiple secondary batteries in series during the charging and connects the multiple secondary batteries in parallel during the discharging.

Abstract: A protection circuit includes a detector to detect an overcharging or an excessive discharging of a battery, from a voltage of a power terminal coupled to the battery, a controller to generate a control signal to stop the charging or the discharging of the battery when a detection of the overcharging or the excessive discharging is continuously detected by the detector for a predetermined time, and a current varying circuit to vary a current flowing through the power terminal only for a certain time when the detector detects the overcharging or the excessive discharging of the battery.

Abstract: A charge controller includes a charge control circuit that, when detecting that a charging power supply is connected, controls the charging transistor to apply the charge current; a first and second control switch element connected in series between one terminal of a secondary battery and an external terminal; and a protection circuit that, when the secondary battery is over-discharged, turns off the first control switch element to stop discharge current and when deeply discharged, turns off the second control switch element. The protection circuit sends a charge inhibit signal to the charge control circuit when the secondary battery is deeply discharged, and while receiving the charge inhibit signal, the charge control circuit keeps the charging transistor off to prevent the charge current from flowing even if detecting that the charging power supply is connected.

Abstract: A charge controller includes a charge control circuit which controls a charging transistor; and a protection circuit that, when the secondary battery is over-discharged, turns off the first control switch element to block discharge current and when the secondary battery is overcharged, turns off the second control switch element to prevent the charge current from flowing. The charge control circuit includes a function of control for applying constant charge current through the charging transistor until the voltage of the secondary battery reaches a predetermined value and switching to control for applying charge current at a constant voltage after the voltage of the secondary battery reaches the predetermined value, and a terminal voltage on the positive electrode side and a terminal voltage on the negative electrode side of the secondary battery are supplied as monitoring voltage to the charge control circuit.