The LTC4361 overvoltage/overcurrent protection controller safeguards 2.5V to 5.5V systems from input supply overvoltage. It is designed for portable devices with multiple power supply options including wall adaptors, car battery adaptors and USB ports.

The LTC4361 controls an external N-channel MOSFET in series with the input power supply. During overvoltage transients, the LTC4361 turns off the MOSFET within 1μs, isolating downstream components from the input supply. Inductive cable transients are absorbed by the MOSFET and load capacitance. In most applications, the LTC4361 provides protection from transients up to 80V without requiring transient voltage suppressors or other external components.

The LTC4361 has a delayed start-up and adjustable dV/dt ramp-up for inrush current limiting. A PWRGD pin provides power good monitoring for V_IN. The LTC4361 features a soft shutdown controlled by the ON pin and drives an optional external P-channel MOSFET for negative voltage protection. Following an overvoltage condition, the LTC4361 automatically restarts with a start-up delay. After an overcurrent fault, the LTC4361-1 remains off while the LTC4361-2 automatically restarts after a 130ms start-up delay.

Applications

• USB Protection
• Handheld Computers
• Cell/Smart Phones
• MP3/MP4 Players
• Digital Cameras