Multi-cell Li-Ion charger with integrated fault protection
The Texas Instruments BQ24742RHDR is a battery charger IC for lithium-ion and lithium-polymer stacks, supporting 2 to 4 series cells with a maximum pack voltage of 18.048 V. Charge current is constant and programmable up to 10 A, which means this part handles the charging budget for a 2S to 4S pack in notebooks, power tools, or portable medical equipment where the charge time target is under an hour. The fault protection block covers over-current, over-temperature, over-voltage, and short-circuit conditions — the four failure modes that most commonly damage a multi-cell pack when the charger loses regulation.
Supply rail and temperature envelope
Maximum supply voltage is 24 V, so the input rail must stay below that absolute-max ceiling; a typical 19 V notebook adapter or 24 V industrial bus is within range, but a 28 V adapter would exceed the rating at the pin. Operating junction temperature spans -40°C to 125°C, which is the full automotive-grade range — the charger can sit on a board near a hot CPU or in an enclosure that sees summer sun without derating the charge current.