BQ29209DRBR

The BQ29209DRBR from Texas Instruments is a specialized integrated circuit designed for secondary overvoltage protection in 2-series cell lithium-ion battery packs. It incorporates a high-accuracy overvoltage detection circuit and an automatic cell imbalance correction feature.

The device compares the voltage of each cell against an internal reference. If an overvoltage condition is detected, it initiates a timer before changing the output state. The automatic cell imbalance correction feature helps maintain voltage balance between cells by loading the cell with the higher charge voltage with a small balancing current, which is removed when cell voltages are within 0 mV. This balancing can be enabled or disabled via an external control pin.

Key electrical specifications include fixed overvoltage protection thresholds of 4.30 V and 4.35 V, with high-accuracy overvoltage protection of ±25 mV within a specific temperature range. It operates with low power consumption, typically less than 3 µA when below the protection voltage. The internal cell balancing can handle currents up to 15 mA, and external balancing modes are also supported.

Packaged in an 8-SON (3x3) or 8-VDFN exposed pad, the BQ29209DRBR is designed for surface mount applications. Its operating temperature range is -40°C to 110°C (TA). This IC is suitable for applications such as netbook computers, power tools, portable equipment, and battery backup systems requiring reliable battery protection.