Battery-pack monitor packs punch into eight-pin package

-- EDN, 4/13/2000

The DS2438 smart battery monitor from Dallas Semiconductor provides an array of battery-pack functions so you can more effectively manage those vital cells. The IC (picture) provides a 64-bit identifying tag, a direct-to-digital temperature sensor, an A/D converter for monitoring battery voltage and current, a gas-gauge current accumulator to measure cumulative current flow, an elapsed-time meter, and 40 bytes of nonvolatile EEPROM in which you can store battery parameters. The monitor works with a microcontroller or system processor, which provides the remaining-charge and charge-control algorithms.The device communicates via a three-contact interface supporting power, ground, and data. The 64-bit code uniquely identifies each IC and, thus, an associated battery pack, so you can wire multiple packs to the same bus but individually address and control them and keep track of which pack is where. Although available now in an SOIC for $1.15 (10,000), the DS2438 will soon also be available in flip-chip packages.

Dallas Semiconductor, www.dalsemi.com.

-by Bill Schweber