Sizing the charge current for your cell capacity
The BQ24081DRCT is a linear charger for one Li-Ion or Li-Polymer cell, with a maximum charge current of 1A. For a typical 2000 mAh pack, that works out to a 0.5C charge rate — expect roughly two hours from empty to full, assuming the input supply can deliver the 1A plus overhead. Charge current and the safety timer are set with external resistors, not through a serial bus — no I2C or firmware involvement needed. This keeps the BOM simple and the charger block independent of the main MCU.
Thermal budget in the 3x3 VSON
At 1A charge current with a 4.2V battery and a 5V input, the linear regulator drops 0.8V, dissipating roughly 0.8W. The 10-VSON (3x3) exposed-pad package needs a solid thermal connection to a copper plane — the datasheet recommends multiple vias under the pad to the ground layer. Without that, the junction temperature climbs above the 85°C industrial limit.
This part is safe to commit to a BOM for a production run without worrying about a near-term last-time-buy window. The device is ROHS3 compliant, which matches current assembly requirements for lead-free reflow.