Single-cell Li-Ion charger with 500 mA ceiling
The Texas Instruments BQ24200DGNR is a linear charge-management IC for single-cell Lithium-Ion and Lithium-Polymer battery packs. It regulates the battery voltage to 4.2 V and delivers a constant charge current programmable up to 500 mA via an external resistor. The part integrates over-temperature and short-circuit fault protection, reducing the external component count for a compact charger section.
13.5 V input ceiling and thermal design
The maximum supply voltage is 13.5 V, so the input rail must be regulated below that — a 12 V bus or a 5 V USB supply works directly, but an unregulated 15 V wall adapter exceeds the rating.
Programmable current and timer
Two programmable features — charge current and charge-termination timer — are set with external resistors. The constant-current charging profile suits single-cell Li-Ion and Li-Polymer chemistries without needing a separate system processor to manage the charge cycle. The timer provides a safety backup if the battery never reaches the 4.2 V regulation threshold.
Active production, sourced to order
No official second-source or pin-compatible alternate is listed in the TI portfolio, so the BQ24200 is the sole direct fit for this BOM position.