2S Li-Ion overvoltage guard in a 3x3 SON
The Texas Instruments BQ29209DRBR is a dedicated battery protection IC for two-series (2S) lithium-ion packs. Its primary job is to monitor each cell for overvoltage conditions and disconnect the pack from charge or discharge when a threshold is exceeded. This is a protection-only part — no fuel-gauging, no SMBus communication, no cell balancing. It sits on the cell-stack PCB, wired directly to the pack terminals, and its output drives the charge/discharge FETs. The 8-SON (3x3) package keeps the footprint small — useful when the protection PCB shares space with the cell interconnect board.
If the BOM calls for a 2S Li-Ion protection IC, this is the correct device class.
ROHS3 compliant.