Single-cell Li-Ion charger with I²C programmability
The Texas Instruments BQ24251RGET is a single-cell lithium-ion battery charger IC in a 24-VFQFN Exposed Pad package (24-VQFN 4x4 mm). It charges a single Li-Ion cell to a 4.2V battery pack voltage with a constant-current charge that is programmable via the I²C interface up to a maximum of 2A.
What the 2A charge current and I²C control mean for your BOM
The 2A maximum charge current sets the charging speed for a single-cell Li-Ion pack — a 2000 mAh cell charges in roughly one hour at that rate. The I²C interface allows the host microcontroller to adjust the charge current dynamically, which is useful for thermal management or charging from a limited-current USB source. The supply voltage maximum is 10.5V, so this part can operate from a 5V USB bus or a higher-voltage wall adapter without an external pre-regulator. Fault protection is built in: over-current, over-temperature, and over-voltage protection are all on-chip, which simplifies the BOM by eliminating external supervisory components.
NRND — not for new designs, but still available
TI is not actively promoting this part for new product introductions, but it remains available for existing production BOMs.
Sourcing for existing BOMs and repairs
For a production BOM that already specifies the BQ24251RGET, securing inventory now avoids a last-time-buy scramble later.