Linear Technology Korea announced the launch of a surge stopper (product name: LTC4380) that protects automotive, industrial, and aviation systems from overvoltage and overcurrent.

The LTC4380 replaces the existing shunt circuit consisting of bulk inductors, capacitors, and TVS (transient voltage suppressors) and forms a simple IC and series N-channel MOSFET solution, thereby saving board space and enabling continuous operation under transient voltage or current surges.

The LTC4380 protects the electronic circuit connected to the downstream end under input overvoltage conditions and protects the power supply from output overload.



The device consumes only 8µA during normal operation and 6µA in shutdown mode, extending battery operation and standby time. The low current can flow from a large filtering resistor to the device power pin, enabling operation under automotive cold crank and overvoltage transients above 100V.

During input voltage surges, such as automotive road dumps, the LTC4380 uses an external MOSFET to drop the excess voltage, and as the gate is clamped, the output becomes a safe voltage. Due to these characteristics, low-rated components can be used in the connected electronic circuits at the downstream end, thereby reducing costs.

The clamp voltage can be selected via a pin for 12V and 24V systems and can also be adjusted using an input Zener diode. During an output overload or short circuit, the LTC4380 regulates the forward path with a current limit set by a sense resistor.

During consistent overvoltage or overcurrent conditions, the MOSFET stress-accelerated timeout function ensures the safe turn-off of the MOSFET. In contrast, traditional protection circuits such as fuses or TVS require repair if they fail.

The LTC4380 withstands reverse voltage inputs, such as those from an inverted battery. An adjustable input low-voltage lockout threshold stops the startup function when the input voltage falls below a specified range, preventing severe battery discharge. This device also controls the inrush current during hot-plugging of the circuit board's power supply.