What this charger does and who specs it
The BQ24100RHLRG4 is a 1-cell Li-Ion/Polymer battery charger from the bqSWITCHER™ series, designed for portable devices that need a constant-current/constant-voltage charge profile with programmable current and timer. It handles a maximum charge current of 2A and accepts a supply voltage up to 16V, making it suitable for USB or 5V/12V adapter inputs.
Sizing the input rail and charge current
With a 16V absolute maximum supply, the BQ24100 can step down from a 12V adapter or a 5V USB port — the input capacitor and inductor must be rated for the peak switch current at the chosen input voltage. The 2A charge current ceiling means a single 18650 cell (typically 2-3 Ah) can be charged in about 1-1.5 hours; the programmable timer prevents overcharge if the termination current is not reached.
Lifecycle and supply posture
It is supplied in Tape & Reel (TR) on a 20-VFQFN Exposed Pad package (3.5x4.5 mm), surface-mount only.
Fault protection and battery chemistry
Built-in fault protection covers over-temperature and over-voltage conditions, reducing external component count for safety compliance. The charger targets a battery pack voltage of 4.2V, which is the standard termination voltage for most Li-Ion and Li-Polymer cells.