What this battery protection IC does for a single Li-ion cell
The BQ24316DSJT is a single-chip battery protection solution for one Li-ion cell, integrating over-current, over-temperature, and over/under-voltage fault protection. The 12-VSON (4x3) package with exposed pad requires a thermal-land pattern on the PCB — the pad area under the IC sets the junction-to-ambient thermal resistance, so the layout needs a copper pour on the top layer and vias to the ground plane to keep the die below the 125°C junction limit.