The GG25L from STMicroelectronics is a Gas Gauge IC that is designed to include the necessary hardware functions required to implement a low-cost gas gauge for battery monitoring applications. It requires an input voltage of 2.7 - 4.5 V. This BMIC consists of an ADC converter, oscillator, control logic and state machine, control registers, MUX, battery detection and control, an internal temperature sensor, memory unit, and external interfaces. It embeds monitoring functions that provide accurate measurements of the battery voltage, current, and temperature.  This IC includes a Coulomb counter to track the state-of-charge (SOC) when the battery is charging or discharging at a high rate.

It utilizes an internal OptimGauge algorithm that precisely simulates the dynamic behavior of the battery and provides an estimate of the open-circuit voltage (OCV). This gas gauge IC accurately senses changes in battery voltage that causes the algorithm to track both the OCV and SOC values while taking non-linear characteristics and time constants of the chemical nature of the Li-ion and Li-Po batteries into account. It signals an alarm during low SOC conditions and allows the users to change the threshold levels of the battery voltage using the I2C bus interface. This BMIC is available in a wafer-level package that measures 1.4 x 2.0 mm and is ideal for portable medical equipment, fitness, healthcare, and wearable applications.