DESCRIPTION

The DS2437 Smart Battery Monitor provides several functions that are desirable to carry in a battery pack: a means of tagging a battery pack with a unique serial number; a direct-to-digital temperature sensor which eliminates the need for thermistors in the battery pack; an A/D converter which measures the battery voltage and current; an integrated current accumulator, which keeps a running total of all current going into and out of the battery; a real-time clock; and 40 bytes of nonvolatile EEPROM memory for storage of important parameters such as battery capacity, capacity remaining, and indication of battery cycling.

Information is sent to/from the DS2437 over a 1-Wire interface, so that only one wire (and ground) needs to be connected from a central microprocessor to a DS2437. This means that battery packs need only have three output connectors: battery power, ground, and the 1-Wire interface.

Because each DS2437 contains a unique silicon serial number, multiple DS2437s can exist on the same 1-Wire bus. This allows multiple battery packs to be charged or used in the system simultaneously.

FEATURES

■ Unique 1-Wire® interface requires only one port pin for communication

■ Provides unique 64-bit serial number to battery packs

■ Eliminates thermistors by sensing battery temperature on-chip

■ On-board A/D converter allows monitoring of battery voltage for end-of-charge and end-of discharge determination

■ On-board integrated current accumulator facilitates gas gauging

■ Real-time clock in binary format

■ 40-byte nonvolatile user memory available for storage of user data such as gas gauge and manufacturing information

■ Operating range -40°C to +85°C

■ Applications include portable computers, portable/cellular phones, consumer electronics, and handheld instrumentation