February 20, 2013, Seoul – STMicroelectronics (ST), a global semiconductor company providing a wide range of electronic applications and a leading supplier of standard ICs, has unveiled its latest battery gauge device, the STC3115. This new product features patented functions that improve long-term accuracy. This compact chip is suitable for mass-produced mobile devices and has been incorporated into some of Samsung's recently released mobile phone models.

Battery charge status gauges have become an essential element of device management for smartphones, laptops, and digital cameras. Accurately predicting remaining battery time not only enhances user convenience but is also a critical issue, particularly for portable medical devices. However, a significant number of current battery gauge products are susceptible to errors caused by battery aging, reduced charging efficiency, leakage, changes in system power demand, and temperature effects.

The new STC3115 adaptive fuel gauge IC incorporates the latest technologies crucial for improving battery gauge accuracy. Major devices to date have monitored energy flow into and out of the battery by measuring Coulomb coefficients or adjusted Coulomb counters by periodically measuring voltage-mode charge states. The STC3115 utilizes OptimGauge™ technology to continuously leverage both of these measurement methods. This technology is an adaptive algorithm that tracks charge states and modifies battery models.

The STC3115 further enhances accuracy by temporarily suspending charging and application start during initial measurement to improve the initial open-circuit voltage measurement of the battery. The charge suppression function is a patented feature that significantly improves accuracy. It features built-in aging and temperature compensation, and the voltage measurement accuracy is 0.25%.

Other features of this new product include a low-power mode that continuously monitors the battery and reduces the operating current to 45µA, and to 2µA in standby mode. Additionally, the UVLO (Under-Voltage Lockout) filter prevents short fluctuations in battery voltage that could cause unwanted system resets. Furthermore, since it operates directly on battery voltage without the need for a built-in voltage regulator, it offers the benefit of reduced material costs.

Key Features of STC3115:
• OptimGauge algorithm that automatically optimizes battery charging/discharging models
• Industry-standard I2C connection to application processor
• Various battery profiles can be programmed during manufacturing (supports various battery types)
• Max 4.5V battery monitor
• Multi-cell pack monitor when using TS941ILT low-power buffer
• Simple battery monitoring with a dedicated battery input
• Warning activated if battery voltage drops below the limit level

The STC3115 is produced in a 1.4 x 2.0mm chip package, and the price is $0.95 per 1,000 units. For larger volume purchases, please contact the ST Korea branch.