Single-cell Li-Ion charger with I²C programmability
The Texas Instruments BQ24153YFFT is a single-cell Li-Ion/Polymer linear charger IC that uses an I²C interface to set the charge current and charge timer. The maximum charge current is 1.25 A, and the battery regulation voltage tops out at 4.44 V. Fault protection covers over-temperature and over-voltage conditions, which is the minimum expected for a portable-device charger in 2025.
1.25 A charge current — sizing the charge time
For a typical 1000 mAh single-cell Li-Ion pack, 1.25 A delivers a 0.8C charge rate — fast enough for a sub-90-minute full charge from empty, but below the 1C threshold that stresses most consumer-grade cells. The charge current is constant and programmable via I²C, so the BOM can tune the rate to the cell's datasheet recommendation without a resistor change.
20-DSBGA — footprint and rework considerations
The 20-DSBGA package (0.4 mm pitch, wafer-level) is the same footprint as the 20-UFBGA option. The small ball array saves board area but demands a solder-mask-defined pad layout and a stencil aperture that matches the ball diameter. Rework requires a hot-air profile with bottom-side preheat; the package is moisture-sensitive, so a bake cycle before reflow is mandatory if the floor life has been exceeded.