2.7V to 18V input, 4A eFuse in 2x2 mm WSON
The Texas Instruments TPS259571DSGT is an integrated electronic fuse (eFuse) in an 8-WSON (2x2) package, designed to protect downstream circuitry from overcurrent, overvoltage, and inrush events on supply rails from 2.7V up to 18V. It delivers a continuous output current of 4A with a current-limit accuracy of ±7.5%, which determines the guard band needed between the trip threshold and the load's peak demand.
Current-limit accuracy and thermal budget
The ±7.5% accuracy on the current-limit threshold means a design targeting a 3.6A continuous load must set the limit no lower than 3.9A to avoid nuisance trips at the low end of the tolerance band, leaving 0.3A of headroom above the nominal load. The 8-WFDFN exposed pad (8-WSON 2x2) package relies on the PCB copper pour under the pad for thermal dissipation; the datasheet's RθJA figure assumes a specific land pattern, so the layout must match the recommended footprint to achieve the rated 4A without hitting the thermal shutdown threshold.