Abstract: Provided are a battery protection IC adaptable to any number of batteries connected in series without increasing a breakdown voltage thereof, and a battery device including the battery protection IC mounted thereon. A charge control signal input terminal and a discharge control signal input terminal of one battery protection IC are provided with a clamp circuit (121), and hence an output driver (112) of another battery protection IC connected to those terminals is not applied with a voltage equal to or higher than a breakdown voltage. Accordingly, the breakdown voltage of the battery protection IC is not required to be high.

Abstract: Provided is a battery state monitoring circuit which is capable of preventing a discharge leak current from a battery so as to eliminate a load conventionally imposed on a user, including: a battery state detector circuit that detects a state of the battery based on a voltage of the battery; a transmitting terminal that transmits battery state information indicative of the state of the battery to an outside; a receiving terminal that receives battery state information of another battery from the outside; a transistor that is used for transmitting the battery state information, and has any one of two terminals except for a control terminal connected to the transmitting terminal; and a diode that is connected in a direction opposite to a direction of a parasitic diode disposed between the two terminals of the transistor, the diode being disposed between the transmitting terminal and one terminal of the transistor.

Abstract: Provided is a battery pack capable of implementing temperature protection with ease. Regardless of whether or not a battery protection IC (11) has a terminal for temperature protection of a battery pack (10), the battery pack (10) is capable of implementing the temperature protection by using an N type FET (15) and a resistor (17). Accordingly, there is no influence of the presence/absence of the terminal on implementing the temperature protection of the battery pack (10). Therefore, the battery pack (10) may implement the temperature protection with ease.

Abstract: Provided are a battery protection IC adaptable to any number of batteries connected in series without increasing a breakdown voltage thereof, and a battery device including the battery protection IC mounted thereon. A charge control signal input terminal and a discharge control signal input terminal of one battery protection IC are provided with a clamp circuit (121), and hence an output driver (112) of another battery protection IC connected to those terminals is not applied with a voltage equal to or higher than a breakdown voltage. Accordingly, the breakdown voltage of the battery protection IC is not required to be high.

Abstract: Provided is a battery state monitoring circuit which is capable of preventing a discharge leak current from a battery so as to eliminate a load conventionally imposed on a user, including: a battery state detector circuit that detects a state of the battery based on a voltage of the battery; a transmitting terminal that transmits battery state information indicative of the state of the battery to an outside; a receiving terminal that receives battery state information of another battery from the outside; a transistor that is used for transmitting the battery state information, and has any one of two terminals except for a control terminal connected to the transmitting terminal; and a diode that is connected in a direction opposite to a direction of a parasitic diode disposed between the two terminals of the transistor, the diode being disposed between the transmitting terminal and one terminal of the transistor.