The LTC4380 low quiescent current surge stopper protects loads from high voltage transients. Overvoltage protection is provided by clamping the gate voltage of an external N-channel MOSFET to limit the output voltage to a safe value during overvoltage events such as load dump in automobiles. Fixed gate clamp voltages are selectable for 12V and 24V/28V systems. For systems of any voltage up to 72V, use the adjustable gate clamp versions. Overcurrent protection is also provided.An internal multiplier generates a TMR pin current proportional to VDSand ID, so that operating time in both overcurrent and overvoltage conditions is limited in accordance with MOSFET stress.The GATE pin can drive back-to-back MOSFETs for reverse input protection, eliminating the voltage drop and dissipation of a Schottky diode solution. A low 8µA operating current permits use in always-on and battery powered applications. An accurate ON pin comparator monitors the input supply for undervoltage (UV) conditions and also serves as a shutdown input, reducing the quiescent current to 6µA.ApplicationsAutomotive/Avionic/Industrial Surge ProtectionHot Swap, Live InsertionHigh Side Switch for Battery Powered SystemsAutomotive Load Dump Protection