Li-ion protection IC in a 2x2 mm WSON
The Texas Instruments BQ24316DSGT is a battery protection IC for single-cell Lithium Ion packs, integrating over-current, over-temperature, and over/under-voltage fault protection in an 8-WSON (2x2) package. This is a charger-side protection device, not a fuel gauge or charger controller — it sits between the charger output and the battery cell, monitoring voltage and current and disconnecting the cell when a fault threshold is exceeded. The junction temperature range spans 0°C to 125°C, covering most portable and industrial environments where a Li-ion pack is present.
Fault protection set and thermal budget
Three fault axes are monitored: over-current (the protection FET's current-limit threshold), over-temperature (die-level thermal shutdown), and over/under-voltage (cell voltage outside the safe operating window). Operating temperature is specified as junction temperature (TJ), not ambient — derate the continuous load current based on the board's thermal resistance and the maximum ambient temperature in the enclosure.