Why this eFuse exists — the discrete alternative it replaces
The TPS259401AQRVCRQ1 is an automotive-grade electronic fuse from Texas Instruments that replaces the discrete PTC fuse + series MOSFET + current-sense resistor + comparator chain with a single IC in a 20-WQFN (4x3) package. It protects a downstream load rail from overcurrent and overvoltage faults without the thermal reset lag of a PTC or the BOM count of a discrete protector. Rated for a continuous output of 5.3 A across a 2.7 V to 18 V input range, it covers the common automotive supply rails — 3.3 V, 5 V, and 12 V — in a single footprint. The ±8% current-limit accuracy means you size the load budget with a tighter guard band than a PTC's ±30% tolerance allows.
125°C operating ceiling — under-hood ready
That covers under-hood, engine-bay, and transmission-mounted electronics where the ambient near the ECU or junction box can hit 105°C and the self-heating of the eFuse adds another 20°C. The 20-WFQFN exposed pad pulls heat into the PCB copper pour — the board layout sets the effective thermal resistance, not the package alone.
That means no last-time-buy notice to track, no end-of-life scramble for a pin-compatible swap.