Li-Ion stack monitor for 2-4 series cells
The BQ29441DRBT is a dedicated battery protection IC from Texas Instruments, designed to monitor and protect 2 to 4 series-connected lithium-ion cells against over-voltage conditions. It operates across a -40°C to 110°C temperature range, making it suitable for both consumer and industrial battery packs that see thermal cycling.
Over-voltage watchdog with no external MCU dependency
The fault protection is limited to over-voltage detection — the IC does not handle over-current, short-circuit, or under-voltage on its own. That means the BOM still needs a separate fuel gauge or protector for those functions. With a 2-4 cell range, it covers common 7.2 V to 14.8 V nominal packs (2S through 4S) used in power tools, e-bikes, and portable medical gear.
8-SON footprint — board layout note
The exposed pad is the primary thermal path, not the leads. Surface-mount assembly with the exposed pad requires a solder stencil aperture that covers at least 50% of the pad area to avoid voids and ensure thermal transfer.