Battery Fuel Gauge Allows Algorithm Customization

The DS2792, a programmable fuel gauge for 1- or 2-cell applications, integrates a microcontroller, large program and data memory, and a measurement system for current, voltage, and temperature. These features provide users with the freedom to completely customize fuel-gauging algorithms in an array of battery-powered products. The device's computing core, a 16-bit MAXQ20 MCU, employs an accumulator-based RISC architecture, backed by a 16-level hardware stack. To program proprietary algorithms, the DS2792 contains three types of memory: programming memory, EEPROM, and RAM. The 8K words of programming memory consist of 4K words of password-protected EEPROM and 4K words of ROM. Data EEPROM consists of 64 words and data RAM is 256 words. On the measurement side, current levels are summed to calculate total current to within 0.5% ±4 mV over a range of ±64 mV. Via a 15 mW sense resistor, current accuracy is within 0.5% ±267 mA over a 4.2A range. Voltage measurements are taken as a 10-bit value over a 0V to 4.99V range with a resolution of 4.88 mV. An integrated sensor measures battery temperature and reports the results as a 10-bit value with a resolution of 0.125°C. The DS2792 is available in a 28-pin, 8 mm x 4 mm lead-free TDFN package. Prices start at $3.28 each/1,000. MAXIM INTEGRATED PRODUCTS, Sunnyvale, CA. (800) 998-8800.