Micropower fuel gauge reduces quiescent current by 4x and size by 3x

January 03, 2013 // By Paul Buckley
Maxim Integrated Products has begun sampling the MAX17048, the industry’s simplest low-power fuel gauge for Lithium-ion (Li+) batteries.

Operating at 23 µA, the battery fuel gauge claims to use 4x less power than competitive devices and even less in micropower hibernate mode, in which the fuel gauge continues to operate. It needs only one external capacitor, not the multiple external devices of competitive devices, so it simplifies design, shrinks solution size by 3x, and reduces costs. The fuel gauge is ideal for portable battery-powered applications where size, cost, and power are critical, such as smartphones, wireless handsets, and mobile accessories, including Bluetooth headsets, portable speakers, fitness devices, and Wi-Fi routers.

Traditional fuel gauge designs require multiple external components including current-sense resistors, which increase both bill of materials (BOM) cost and design complexity. Those fuel gauges also use coulomb counting, which can drift and affect the accuracy of the gauge over time. The MAX17048 features the proven ModelGauge algorithm and does not require coulomb counting to report accurate battery state-of-charge, thus extending runtime. The MAX17048 functionality is also integrated into the company’s TINI Power System-on-Chip (SoC) to make it easier to upgrade designs to more complex systems.

The device’s ModelGauge algorithm provides accurate state of charge and compensates for temperature and load variation.  The algorithm also eliminates the need for the current-sense resistor required in competing coulomb-counting fuel gauges.

The MAX17048 automatically detects when the battery enters a low-current state and switches into a low-power 4 µA hibernate mode, while still providing accurate fuel gauging. The IC automatically exits hibernate mode when the system returns to active state.  The MAX17048 functionality is available in a Power SoC with identical IP to facilitate a complete power-management solution in a shortened time to market.

Availability and Pricing

The MAX17048 is available in an 8-bump WLP package (0.9 mm x 1.7 mm) and an 8-pin TDFN package (2 mm x 2 mm).  Pricing starts at $1.12 (1000-up, FOB USA).

Visit Maxim Integrated at www.maximintegrated.com