Date: 25/10/2011

Coulomb-counting fuel gauge IC for single-cell Li+ battery packs

Maxim Integrated Products has introduced the MAX17047 coulomb-counting fuel gauge for single-cell Li+ battery packs. Maxim says MAX17047 is the industry's only coulomb-counting fuel gauge that does not suffer from the abrupt corrections that occur with traditional coulomb-counter algorithms. Compared to other coulomb-counters, this ModelGauge m3 IC uses a smaller current-sense resistor and fewer external components, claims Maxim. The IC is suggested as ideal for fuel-gauging handheld single-cell and multicell Li+ batteries in a wide range of portable applications, including wireless handsets, smartphones, tablets, e-readers, portable game players, digital cameras, financial terminals, portable navigation equipment, and portable medical equipment.

Maxim explains traditional Li+ battery fuel gauges are mounted inside the battery pack and require multiple supporting discrete components. To estimate of battery capacity, the fuel gauges rely on coulomb counters. These coulomb counters have a problem because of the small ADC offset errors that accumulate indefinitely. To correct for these offset accumulation drifts, a large and expensive sense resistor is needed. In addition, the battery must go into full, empty, or standby states on a regular basis, as per Maxim.

Availability, package and price: The MAX17047 ModelGauge m3 fuel gauge is packaged in a lead-free, 10-pin, 3mm x 3mm TDFN. It communicates with the system microprocessor over an industry-standard 2-wire interface. Prices start at $1.24 (10k-up, FOB USA).

For more information, visit: http://www.maxim-ic.com/ModelGauge.