I²C-programmable charge current for 1-4 cell Li-Ion packs
This is a switch-mode battery charger controller for Lithium Ion packs, supporting 1 to 4 series cells with a maximum battery pack voltage of 19.2 V. The charge current is constant and programmable via the I²C interface — you set the current level in firmware rather than swapping a sense resistor, which simplifies BOM changes across different pack capacities. Supply voltage goes up to 24 V, so it works from common 19 V laptop adapters or 24 V industrial rails. The integrated fault protection covers over-current, over-voltage, and short-circuit conditions, reducing the need for external supervisory circuitry.
20-VFQFN with exposed pad — layout checklist
The package is a 20-VFQFN with an exposed pad, 3.5 x 3.5 mm body (supplier device package 20-VQFN). Surface-mount only. Store the reels dry; this QFN is moisture-sensitive and needs a bake before reflow if the seal is broken.
That is a commercial-to-hot range — fine for consumer notebooks, docking stations, and indoor industrial chargers, but not rated for the -40°C cold start an automotive or outdoor telecom design would need.