Abstract: A composite integrated circuit includes a protection IC that controls a switching circuit inserted in a power supply line to allow or prevent discharging of the secondary battery, and a monitoring IC that includes a ground terminal connected to the power supply line at a position between the secondary battery and the switching circuit, measures a voltage of the secondary battery, and sends the measured voltage to an external apparatus. The protection IC outputs an activation signal to turn on the switching circuit to allow discharging of the secondary battery, and outputs a deactivation signal to turn off the switching circuit to prevent discharging of the secondary battery. The monitoring IC consumes less power while the deactivation signal is output by the protection IC than the monitoring IC consumes while the activation signal is output by the protection IC.

Abstract: A multichip in which a protection IC for detecting at least one of overcharge, over discharge, and overcurrent of a secondary battery and a monitoring IC for monitoring a battery state of the secondary battery are integrated in a package. The protection IC and the monitoring IC are not overlapped in a plan view. A regulator output terminal for the monitoring IC, a ground terminal common to the protection IC and the monitoring IC, a power supply terminal common to the protection IC and the monitoring IC, and a current detection terminal for the protection IC are disposed along a first side of package, and a communication terminal for the monitoring IC, a discharge control terminal for the protection IC, a charge control terminal for the protection IC, and a overcurrent detection terminal for the protection IC are disposed as external connection terminals along the second side of package.

Abstract: A composite integrated circuit includes a protection IC that controls a switching circuit inserted in a power supply line to allow or prevent discharging of the secondary battery, and a monitoring IC that includes a ground terminal connected to the power supply line at a position between the secondary battery and the switching circuit, measures a voltage of the secondary battery, and sends the measured voltage to an external apparatus. The protection IC outputs an activation signal to turn on the switching circuit to allow discharging of the secondary battery, and outputs a deactivation signal to turn off the switching circuit to prevent discharging of the secondary battery. The monitoring IC consumes less power while the deactivation signal is output by the protection IC than the monitoring IC consumes while the activation signal is output by the protection IC.

Abstract: A multichip in which a protection IC for detecting at least one of overcharge, over discharge, and overcurrent of a secondary battery and a monitoring IC for monitoring a battery state of the secondary battery are integrated in a package. The protection IC and the monitoring IC are not overlapped in a plan view. A regulator output terminal for the monitoring IC, a ground terminal common to the protection IC and the monitoring IC, a power supply terminal common to the protection IC and the monitoring IC, and a current detection terminal for the protection IC are disposed along a first side of package, and a communication terminal for the monitoring IC, a discharge control terminal for the protection IC, a charge control terminal for the protection IC, and a overcurrent detection terminal for the protection IC are disposed as external connection terminals along the second side of package.