An electronic fuse eliminates fuse replacement in case of an overload and does not dissipate any power under short-circuit conditions as a current-limiter circuit would.
Shown below is a two transistor (one PNP BJT and one P-MOSFET) version of a DC, high-side electronic fuse for positive voltages.
Reversing the transistor polarities to NPN and N-MOSFET would give a high-side fuse for negative voltages.
Q1 monitors the voltage across the shunt resistor R1. When the current increases so that...