The BQ24702PWRG4 is a multi-chemistry battery charge controller from Texas Instruments, rated for a maximum supply voltage of 28V. That 28V ceiling covers common adapter rails like 19V laptops and 24V industrial supplies without needing a pre-regulator — but you lose headroom if the adapter can spike above 28V during hot-plug or load dump. It supports multi-chemistry charging, which means one BOM line can handle Li-ion, Li-Polymer, and NiMH packs by swapping the charge algorithm in firmware — useful for a product line that ships with different battery types.
The 85°C ceiling is the ambient limit, not the junction — the TSSOP's thermal pad (if present) and board copper area set the real thermal budget at full charge current.
Sourcing and lifecycle posture
The BQ24702 base number shares the same pinout across the family, so if TI ever phases out the PWRG4 tape-and-reel variant, the tube-packaged BQ24702PW would be the drop-in replacement without a board spin.