Single-cell Li-ion charger with I²C programmability
The Texas Instruments BQ24140YFFR is a single-cell Li-Ion/Li-Polymer battery charger IC with an I²C interface for programmable charge current and timer settings. It delivers up to 1.5 A charge current to a single cell with a maximum battery pack voltage of 4.44 V, covering standard 4.2 V and 4.35 V termination voltages. Built-in fault protection includes over-temperature and over-voltage shutdown, reducing external component count for a compact charger design.
The 1.5 A maximum charge current suits single-cell Li-ion packs in the 1000–3000 mAh range, delivering a 1C to 0.5C charge rate that balances charge time and cell longevity. The programmable current feature lets you adjust the rate via I²C to match the cell manufacturer's recommended charge profile. With a battery pack voltage ceiling of 4.44 V, this part supports both standard 4.2 V Li-ion cells and the higher-voltage 4.35 V Li-Po chemistries common in slim portable devices. The 9 V maximum supply input gives headroom for 5 V USB or 9 V wall adapters.
Package and thermal considerations for the 30-DSBGA
The 30-DSBGA package (30-UFBGA, DSBGA) is a fine-pitch BGA with 0.5 mm ball pitch, requiring a 4-layer PCB with thermal vias under the die pad to dissipate heat from the 1.5 A charge pass element. Surface-mount assembly with a standard lead-free reflow profile works, but the small BGA body demands precise solder paste volume and X-ray inspection for voiding under the thermal pad.