Advanced, Smart Battery-Pack Controllers

The MAX1789/MAX17892 smart battery-pack controllers integrate a user-programmable microcontroller core, a coulomb-counting fuel gauge, a multichannel data-acquisition unit, and a system management bus (SMBus™) v1.1-compliant master/slave SMBus interface. The 8-bit, RISC microcontroller core has an integrated 8kB of user-programmable flash and a 12kB program ROM library, which provides battery-pack designers with complete flexibility in developing fuel gauging and control algorithms. The MAX1789/MAX17892 are equipped with in-system debug (ISD) capability for efficient development and debugging.

The MAX1789/MAX17892 include a 12-bit data-acquisition unit to measure individual cell voltages, thermistors, current, and pack voltage. 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 MAX1789/MAX17892 have a wide +4V to +25V operating voltage range. The MAX1789/MAX17892 are available in a lead-free, 28-pin TSSOP package. The MAX1789/MAX17892 evaluation kit is available to assist with development.

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 Error

* 139nAh Resolution (5mΩ)

* No Calibration Required

* 8-Bit RISC Microcontroller Core

* 8kB of Program Flash

* 12kB of Program ROM

* 512 Bytes of Data Flash

* 648 Bytes of RAM

* 12-Bit ADC

* Watchdog Timer

* In-System Debug

* Eliminates Separate Primary-Protection IC

* Individual Cell-Voltage Measurements with 0.5% Accuracy

* n-Channel MOSFET Gate Drivers

* Low-Current Charge Pump

* 8% Accurate Overcurrent Protection

* Programmable Overcurrent Delay Timers

* 3-Pin, 6-LED PWM Driver (Only for MAX1789)

* Random-Number Generator (RNG) for Encryption

* SMBus v1.1 Compliant with Master Capability

* Typical Operating Current < 250µA

* Typical Shutdown Current < 10nA

* Integrated 32kHz Oscillator: No Crystal

* Fully Integrated LDO (VIN = +4V to +25V)