The MAX1781 smart battery-pack controller integrates a user-programmable microcontroller core, a coulomb-counting fuel gauge, a multi-channel data-acquisition unit, and an SMBus v1.1 compliant master/slave SMBus interface. The 8-bit, RISC microcontroller core has an integrated 12k bytes of user programmable EEPROM, which provides battery-pack designers with complete flexibility in developing fuel gauging and control algorithms. The MAX1781 is equipped with full ICE (in-circuit emulator) capability for efficient firmware development and debugging. The 16-bit data-acquisition unit measures individual cell voltages, cell stack voltage, chip internal/external temperature, and two general purpose analog inputs. Individual cell voltage measurements with 0.5% accuracy and over-current protection allow the MAX1781 to eliminate a separate 1st level protection IC. Adjustable over-current 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 MAX1781 has a wide 4V to 28V operating voltage range. The IC is available in a 7mm x 7mm 48-TQFN package with a maximum thickness of 0.8mm. Applications * Data Acquisition Systems * Notebook Battery Packs * Proprietary Battery Packs * Remote Data Logging * Accurate Fuel Gauge Uses V to F Method * < 1µV Input Offset Voltage * < 1% Gain Accuracy * No Calibration Required * 8-bit RISC Microcontroller Core * 12k Bytes of Program/Data EEPROM * 64 Bytes of Byte Writeable EEPROM * 264 Bytes of RAM * Watchdog Timer * ICE for Firmware Debugging * Integrated Development Environment (IDE) * C Compiler * Inline Assembler * Eliminates Separate Primary-Protection IC * Individual Cell Voltage Measurements with 0.5% accuracy * Built-In Protection MOSFET Gate Drivers * 8% Accurate Overcurrent Protection * Programmable Over-Current Delay Timers * SMBus v1.1-Compliant, with Master Capability * Typical Operating Current < 120µA * Typical Shutdown Current < 10nA * Integrated 32kHz Oscillator: No Crystal * Fully Integrated LDO (VIN = 4V to 28V)