5.2µA 1-Cell Fuel Gauge with ModelGauge m5 EZ and Internal Current Sensing

The MAX17262 is an ultra-low power fuel-gauge IC which implements the Maxim ModelGauge™ m5 algorithm. The IC monitors a single-cell battery pack and supports internal current sensing. The IC provides best performance for batteries with 30mAhr to 6Ahr capacity.

The ModelGauge m5 EZ makes fuel-gauge implementation easy by eliminating battery characterization requirements and simplifying host software interaction.The ModelGauge m5 EZ robust algorithm provides tolerance against battery diversity for most lithium batteries and applications.

The ModelGauge m5 EZ algorithm combines the short-term accuracy and linearity of a coulomb counter with the long-term stability of a voltage-based fuel gauge, along with temperature compensation to provide industry-leading fuel-gauge accuracy. The IC automatically compensates for cell-aging, temperature, and discharge rate, and provides accurate state-of-charge (SOC) in percentage (%) and remaining capacity in milliampere-hours (mAh) over a wide range of operating conditions. As the battery approaches the critical region near empty, the ModelGauge m5 algorithm invokes a special correction mechanism that eliminates any error. The IC provides accurate estimation of time-to-empty and time-to-full and provides three methods for reporting the age of the battery: reduction in capacity, increase in battery re- sistance, and cycle odometer.

The IC provides precision measurements of current, voltage, and temperature. The temperature of the battery pack is measured using an internal temperature sensor or external thermistor. A 2-wire I2C interface provides access to data and control registers. The IC is available in a tiny lead-free 0.4mm pitch, 1.5mm x 1.5mm, 9-pin wafer-level package (WLP).

APPLICATIONS

* Bluetooth Headset Cases * Handheld Computers and Terminals * Health and Fitness Monitors * Home and Building Automation, Sensors * Medical Devices * Toys * Wearables and Smartwatches

* ModelGauge m5 EZ

* No Characterization Required for EZ Performance

* Robust Against Battery Variation

* Eliminates Error Near Empty Voltage

* Eliminates Coulomb Counter Drift

* Compensates for Age, Current, Temperature

* Does Not Require Empty, Full, or Idle States

* Low 5.2µA Operating Current

* Integrated Current Sensing Options

* 7mΩ and 30mΩ (typ)

* Supports Li+ and Variants Including LiFePO4

* Thermistor or ±1°C Internal Temperature

* Dynamic Power Estimates Power Capability During Discharge

* Time-to-Empty and Time-to-Full Estimation

* Constant Power or Constant Current

* Predicts Remaining Capacity Under Theoretical Load

* No Calibration Required

* Alert Indicator for Voltage, SOC, Temperature, Current, and 1% SOC Change