DS2437

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. Applications for the smart battery pack monitor include portable computers, portable/cellular telephones, and handheld instrumentation battery packs in which it is critical to monitor real-time battery performance. Used in conjunction with a microcontroller in the battery pack or host system, the DS2437provides a complete smart battery pack solution that is fully chemistry-independent. The customization for a particular battery chemistry and capacity is realized in the code programmed into the microcontroller and DS2437 EEPROM, and only a software revision is necessary should a designer wish to change battery pack chemistry.