Dallas, Texas The DS2786 open-circuit-voltage (OCV) based fuel gauge, released by the Dallas Semiconductor division of Maxim, estimates the available capacity of rechargeable Li+ batteries using a combination of an OCV battery model and coulomb counting. The OCV model measures cell voltage in the open-circuit state and determines battery capacity based on a lookup table stored in the IC.
The accuracy of an OCV-based fuel gauge is dependent on the accuracy of the pack-voltage measurement. The DS2786's 12-bit voltage measurement is accurate within 10mV with a resolution of 1.22 mV. In addition, the DS2786 contains two auxiliary voltage inputs that are designed to measure resistor ratios, making them well-suited for measuring thermistor or pack-identification resistors. Current is measured bidirectionally with a resolution of 11 bits and an LSB value of 25 microvolts. Internal temperature measurements are available with an accuracy of 3 degrees Celsius and a resolution of 0.125 degrees Celsius.
Pricing: Begins at $1.22 each in 10,000-piece quantities
Data Sheet: http://datasheets.maxim-ic.com/en/ds/DS2786.pdf
Dallas Semiconductor/Maxim, 408-737-7600, www.maxim-ic.com