Single-cell Li-ion charger with a wide input window
The BQ24018DRCR is a linear charger for one-cell lithium-ion or lithium-polymer packs, delivering up to 1A programmable charge current from a supply rail that can go as high as 16.5V. That input range covers USB 5V, 12V wall adapters, and unregulated DC bricks without needing a separate pre-regulator — one less part on the BOM. It belongs to the bqTINY™ series, which means the die is optimised for small portable gear where board area and thermal budget are tight.
Programmable current and timer — no I²C needed
Charge current and safety timer are set with external resistors, so no digital interface is required. That simplifies the firmware — the charger runs standalone once the PROG resistor is chosen. The constant-current phase is programmable, and the part terminates charge when the current drops below the threshold or the timer expires. Fault protection covers short-circuit on the output, which is the failure mode you see when a battery tab touches the shield or a connector pin folds over. The part shuts down the pass FET and latches off until the fault is cleared and the input is recycled.