What the BQ24250CYFFT does on the board
The BQ24250CYFFT is a single-cell Li-Ion battery charger IC from Texas Instruments, packing a 2A max charge current into a 30-DSBGA package. It talks to the host over I²C, which means the charge current, termination voltage, and safety thresholds get set in firmware rather than with external resistors. Supply rail goes up to 10.5 V, so it handles typical 5 V USB input with headroom for a 4.2 V battery pack voltage. The programmable constant-current charge profile suits designs where the charge rate needs to vary with input source or battery temperature.
Package reality for the layout engineer
30-UFBGA, DSBGA — that is a 30-ball wafer-level chip-scale package. The 0.4 mm ball pitch demands a controlled impedance stack-up and careful via fan-out under the die. No exposed thermal pad; the heat flows through the BGA balls into the PCB copper, so the inner-layer ground planes do the thermal work. Surface-mount only, and the reflow profile must follow the DSBGA moisture sensitivity level — bake before rework if the parts have been exposed to ambient humidity beyond the floor life.
Protection features that matter in the field
Over-temperature and over-voltage fault protection are built in — no external supervisor needed. The over-voltage clamp catches input transients before they reach the battery FET, and the thermal regulation folds back charge current when the die hits the threshold, not when the case burns your finger. The 1-cell Li-Ion chemistry support means it targets portable devices, IoT endpoints, and handheld instruments.