DS2786BG+

The DS2786BG+ by Analog Devices / Maxim Integrated is a stand-alone OCV-based fuel gauge IC designed for rechargeable Li-ion and Li+ polymer batteries. It estimates available battery capacity by measuring open-circuit voltage (OCV) following a relaxation period, utilizing an on-chip lookup table. For periods of moderate to high discharge rates that preclude OCV measurements, it employs coulomb counting as a secondary capacity estimation method.

This IC reports remaining capacity in percent, along with cell voltage, current, and temperature information. Cell characteristics and application parameters are stored in on-chip EEPROM. Measurement and estimated capacity data are accessed via an I2C interface. The DS2786BG+ includes an on-die temperature sensor and supports resistance measurements of a pack identification resistor and thermistor through two auxiliary inputs.

Intended for the host side of portable devices or within a battery pack, the DS2786BG+ features a 12-bit battery voltage measurement with ±10mV accuracy and an 11-bit bidirectional current measurement capable of ±3.4A. It operates within a -20°C to 70°C temperature range and is housed in a 10-pin, lead-free, 3mm x 3mm TDFN package with an exposed pad.

Key features include accurate low-battery warnings even on the first cycle without a learn cycle, low power consumption with typical active current of 50µA and sleep current of 1µA. The device is suitable for applications such as 3G Multimedia Wireless Handsets, Digital Still Cameras, and Digital Audio (MP3) Players.