LTC4381 Low Quiescent Current eFuse with Surge Protection

Product Details

The LTC4381 is an integrated solution for low quiescent current eFuse with an internal 9mΩ N-Channel MOSFET. Overvoltage protection is provided by clamping the gate voltage of an internal 9mΩ N-channel MOSFET to limit the output voltage to a safe value during overvoltage events such as load dump in automobiles. The MOSFET safe operating area is production tested and guaranteed for the stresses during high voltage transients. Fixed output clamp voltages are selectable for 12V and 24V/28V systems. For systems of any voltage up to 80V, use the adjustable clamp versions.

Overcurrent protection is also provided. An internal multiplier generates a TMR pin current proportional to VDS and 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 6μA operating current permits use in always-on and battery powered applications.


  • Automotive 12V, 24V and 48V System
  • Avionic/Industrial Surge Protection
  • Hot Swap/Live Insertion
  • High Side Switch for Battery Powered Systems
  • Automotive Load Dump Protection

Features and Benefits

  • Withstands Surge Voltages Up to 100V
  • Internal 9mΩ N-Channel MOSFET
  • Guaranteed Safe Operating Area: 20ms at 70V, 1A
  • Low Quiescent Current: 6μA Operating
  • Operates Through Automobile Cold Crank
  • Wide Operating Voltage Range: 4V to 72V
  • No Input TVS Needed
  • Overcurrent Protection
  • Selectable Internal 28.5V/47V or Adjustable Output Clamp Voltage
  • Reverse Input Protection to –60V
  • Adjustable Turn-On Threshold
  • Adjustable Fault Timer with MOSFET Stress Acceleration
  • Latchoff and Retry Options
  • Low Retry Duty Cycle During Faults
  • 32-Lead DFN (7mm × 5mm) Package