The Texas Instruments TPS259573DSGR is an electronic fuse (eFuse) in an 8-WSON (2x2) package, designed to protect downstream circuitry from overcurrent, overvoltage, and inrush events. The ±7.5% accuracy on the current-limit threshold means the design needs to budget for a wider trip window than a precision current-sense solution — fine for general-purpose load switching and hot-swap protection, but not for tight overcurrent guard bands. It is an active, ROHS3-compliant part with no end-of-life risk.
The 2.7V to 18V input range covers common 3.3V, 5V, 12V, and 15V power buses. At the low end, 2.7V is enough margin for a 3.3V rail with some droop during cold-crank or brownout. At the high end, 18V handles 12V rails with transients, but if your system sees 24V or 48V nominal, this part is out of spec — step up to a higher-voltage eFuse like the TPS26610 (50V input).
4A output current — load budget and derating
The 4A continuous output rating is the absolute maximum; real-world derating depends on ambient temperature, airflow, and PCB thermal design. For loads above 3A continuous, verify the thermal simulation against the package's theta-JA.
Package and footprint — what to watch on the board
The 8-WSON (2x2) package is small — 2 mm x 2 mm — which helps on dense boards but concentrates heat. Without those vias, the 4A rating is theoretical. The part is surface mount only; no through-hole variant exists. Cut Tape and Tape & Reel options are available for prototyping and production respectively.
The TPS259573DSGR is an active, current-production part from Texas Instruments. It is ROHS3 compliant. The base product number is TPS259573, so variants with different accuracy or current options exist under the same family.