800 mA single-cell linear charger with LiFePO4 support
The Texas Instruments BQ25170JDSGR is a linear battery charger IC designed for single-cell (1S) packs. It handles both lithium-ion/polymer and lithium iron phosphate (LiFePO4) chemistries, with a programmable charge current up to 800 mA and a battery termination voltage up to 4.4 V.
Charge current and thermal limits in the 2x2 WSON
Maximum charge current is 800 mA, constant-current programmable via an external resistor. In the 8-WSON (2x2 mm) package with exposed pad, the thermal design must sink about 0.5 W at full current from a 5 V input to a 3.7 V cell.
Integrated fault protection and programmable features
Overcurrent, overvoltage, overtemperature, and short-circuit protection are built in, reducing external supervisory circuitry. Three programmable parameters — charge current, timer, and termination voltage — let the BOM tune the charge profile to the specific cell type without firmware changes.