Battery circuit with three-terminal memory device

摘要

This invention includes a memory device having exactly three external terminals: a power external terminal; a ground or return external terminal; and a one-wire data communication external terminal. The memory is preferably employed in a rechargeable battery pack having exactly four terminals. The power external terminal is coupled to a battery terminal traditionally used for a thermistor. When a host device desires to read data from the memory, the host device closes a switch coupled between a power source and the thermistor battery terminal, thereby actuating the memory. The host then reads data by way of a communication channel established between a microprocessor in the host device and the data communication external terminal of the memory.