3A single-cell charger in a 2.8x2.5 mm DSBGA
The BQ25898CYFFT is a single-cell Li-Ion/Polymer charger IC from Texas Instruments, delivering up to 3A charge current from a 14V max input supply. The 42-DSBGA package (2.8x2.5 mm) keeps the footprint small, but the thermal budget is real — 3A through a DSBGA demands a solid PCB copper pour under the package and good airflow or a heatsink on the enclosure. The I²C and USB interface allows the host to program charge current, termination voltage, and fault thresholds on the fly — useful when the same board must charge different cell capacities without a hardware change.
Supply voltage ceiling and fault protection
The 14V supply max means this part can survive a 5V USB adapter, a 9V adapter, or a 12V barrel jack without an external pre-regulator. The built-in over-voltage and over-temperature protection gives the board a second line of defense if the input rail glitches.
The part is ROHS3 compliant.
DSBGA rework and layout notes
The 42-DSBGA (2.8x2.5) package is a 0.4 mm pitch ball array. The rework profile needs a pre-bake at 125°C for 8 hours per J-STD-033 if the parts have been exposed to ambient humidity — the small ball diameter traps moisture. On the layout side, the I²C bus lines need pull-up resistors to the host's logic rail; the USB DP/DN lines need 27-ohm series resistors close to the connector for signal integrity.