Smart Battery-Pack Controller

The MAX1785 smart battery-pack controller integrates a user-programmable microcontroller core, a Coulomb-counting fuel gauge, a multichannel data-acquisition unit, and an SMBus™ v1.1-compliant master/slave interface. The 8-bit RISC microcontroller core has an integrated 32kB of user-programmable flash, which provides battery-pack designers with complete flexibity in developing fuel gauging and control algorithms. The MAX1785 is equipped with in-system debug (ISD) capability for efficient firmware development and debugging.

The MAX1785 includes a 12-bit data-acquisition unit to measure individual cell voltages, thermistor, instant current, and pack voltage. Individual cell voltage measurements with 0.5% accuracy and overcurrent protection allow the MAX1785 to eliminate a separate first-level protection IC. Internally adjustable overcurrent thresholds and delay timers provide a flexible solution.

The integrating fuel gauge module provides a typical input offset of less than 1µV and gain accuracy of better than 1% with no trimming required during pack manufacture. The MAX1785 has a wide 4V to 25V operating voltage range. The MAX1785 is available as a 38-pin TSSOP. The MAX1785 EV kit is available to assist with development.

Applications

* Notebook Battery Packs * Proprietary Battery Packs * Remote Data Logging

* Accurate Fuel Gauge Uses V-to-F Method

* 8-Bit RISC Microcontroller Core

* 32kB of Program Flash

* 512 Bytes of Data Flash

* 776 Bytes of RAM

* 12-Bit ADC

* Watchdog Timer

* In-System Debug for Firmware Debugging

* Integrated Development Environment