BQ25185

The BQ25185 is a highly integrated battery charger IC designed for single-cell lithium-ion and lithium-polymer batteries, manufactured by Texas Instruments. It supports both constant-current and constant-voltage charging modes, ensuring safe and efficient battery management. The device features an integrated high-efficiency synchronous buck converter that delivers up to 96% charge efficiency, minimizing power loss and heat generation. This charger includes comprehensive protection features such as overvoltage, overcurrent, thermal shutdown, and short-circuit protection, enhancing system reliability in demanding environments. It also supports USB Power Delivery (PD) and legacy charging protocols, making it suitable for a wide range of input sources including USB ports, wall adapters, and other power supplies. The BQ25185 operates with a wide input voltage range from 4.5 V to 28 V, enabling flexibility in various application scenarios. Integrated into the IC is a precision current regulation circuit that allows accurate charge current control down to 1 mA, ideal for low-power applications. Its programmable charge termination current ensures optimal battery health and longevity. Additionally, the device offers configurable charge timing through external resistors or I²C interface, providing design flexibility for different battery capacities and usage patterns. The BQ25185 supports smart charging algorithms, including pre-charge for deeply discharged batteries, fast charge, and trickle charge phases, all managed automatically without external intervention. A built-in temperature monitoring system using an external thermistor further enhances safety by adjusting charge current based on battery temperature conditions. Designed for compact applications, the BQ25185 comes in a small 3 mm × 3 mm WSON package, reducing board space requirements while maintaining high performance. It also includes a low quiescent current mode (less than 1 μA in shutdown), which is critical for battery-powered devices where power conservation is essential. Applications include portable medical devices, wearables, IoT sensors, wireless earbuds, and handheld tools—any system requiring reliable, efficient, and safe single-cell battery charging. Its robust feature set and ease of integration make it a preferred choice for engineers seeking a complete charging solution in space-constrained designs.