Multichemistry Battery Fuel Gauge

All versions are No Longer Available.

The DS2751 multichemistry battery fuel gauge is a data-acquisition and information-storage device tailored for cost-sensitive and space-constrained 1-cell Li+/polymer or 3-cell Ni battery-pack applications. The DS2751 provides the key hardware components required to accurately estimate remaining capacity by integrating low-power, precision measurements of temperature, voltage, current, and current accumulation, as well as nonvolatile (NV) data storage, into the small footprint of a 3.0mm x 4.4mm 8-pin TSSOP package.

Through its 1-Wire® interface, the DS2751 gives the host system read/write access to status and control registers, instrumentation registers, and general-purpose data storage. Each device has a unique factory-programmed 64-bit net address that allows it to be individually addressed by the host system, supporting multibattery operation.

The DS2751 performs temperature, voltage, and current measurement to a resolution sufficient to support process-monitoring applications such as battery charge control and remaining capacity estimation. Temperature is measured using an on-chip sensor, eliminating the need for a separate thermistor. Bidirectional current measurement and accumulation are accomplished using either an internal 25mΩ sense resistor or an external device. The DS2751 also features a programmable I/O pin that allows the host system to sense and control other electronics in the pack, including switches, vibration motors, speakers, and LEDs.

Three types of memory are provided on the DS2751 for battery information storage: EEPROM, lockable EEPROM, and SRAM. EEPROM memory saves important battery data in true NV memory that is unaffected by severe battery depletion, accidental shorts, or ESD events. Lockable EEPROM becomes ROM when locked to provide additional security for unchanging battery data. SRAM provides inexpensive storage for temporary data.