Linear Technology’s Surge Stopper products solve the deficiencies of the TVS and fuse based shunt circuit. A Surge Stopper IC, such as the LT4363, controls a series N-channel MOSFET, placed between the power supply and the load. During normal operation, the LT4363 fully turns on the MOSFET to provide a low resistance path for the load current. When the input supply voltage surges, the output is regulated to a 2% accurate voltage set by a feedback resistive divider. The output waveform shows a 27V output regulation voltage for a 12V system as the input supply surges to a 250V peak. The precise clamping affords lower-cost 30V capable load electronics. Similarly, during overload or an output short-circuit, the current is limited to a value set by a sense resistor. Both the voltage and current regulation loops activate for an adjustable timer period, allowing the system to ride-through transient faults. The timer protects the MOSFET by turning it off for sustained or DC faults so that there is no component requiring replacement. The low-profile surface-mounted Surge Stopper solution enables a compact system form factor while the accurate voltage and current regulation loops minimize overdesign and reduce cost.