Charger for single-cell Li-ion packs
The BQ24120RHLRG4 is a single-cell Lithium Ion/Polymer charger from TI's bqSWITCHER™ series. It delivers constant - programmable charge current up to 2A from a supply rail as high as 16V.
Programmable current and timer
Charge current is set by an external resistor — no digital interface required. The timer provides a safety timeout; if the battery doesn't reach the 4.2V regulation voltage within the window, the charge cycle terminates. Over-temperature protection shuts down the die if the junction exceeds the thermal limit, which is the primary safeguard given the lack of a dedicated NTC input.
Active production, tape-and-reel delivery
It ships in Tape & Reel (TR) format, surface-mount. The base product number is BQ24120; the RHL suffix identifies the 20-VQFN package variant, and the G4 denotes RoHS-compliant green molding compound.
Thermal and layout notes for the 20-VQFN
The 3.5x4.5 mm body is small enough for handheld designs but demands careful solder-paste stencil design to avoid bridging on the fine-pitch perimeter pads.