摘要 |
Suppression malfunction of an authentication circuit for authenticating a battery pack. Signal line for applying an intermediate potential between the power supply and ground and for reading the potential of a thermistor for detecting the temperature is used as a transmission path for exchanging data between a battery pack and main device. A master-authentication circuit and slave-authentication circuit comprise level-correction circuits, which are connected to the signal line by way of a voltage-comparator circuit. The level-correction circuits are constructed such that they correct the signal applied to the signal line so that it is greater than or less than the unstable-region voltage, and outputs it to the input end of the authentication circuits, so that unstable-region voltage is not applied to the input end. Output circuits overlap in turn authentication information onto the signal line when performing authentication, and the level-correction circuits receive the respective information, and authentication is performed.
|