**LTC4380IDD-2#PBF: A Low IQ Surge Stopper for Robust System Protection**

In today's complex electronic systems, voltage transients and surges pose a constant threat to system integrity and longevity. The **LTC4380IDD-2#PBF** from Analog Devices emerges as a critical solution, offering robust protection with remarkably low quiescent current. This surge stopper IC is engineered to safeguard sensitive downstream components by isolating them from destructive voltage spikes and fault conditions, ensuring reliable operation in harsh electrical environments.

The core functionality of the LTC4380IDD-2#PBF lies in its ability to regulate the output voltage during an overvoltage event. Unlike traditional protection schemes that rely on fuses or crowbar circuits—which can be destructive and require manual intervention—this device utilizes a **unique linear MOSFET control architecture**. It smoothly controls an external N-channel MOSFET in its linear region, maintaining a constant output voltage despite an rising input surge. This "surge stopping" action effectively clamps the output, protecting loads from harmful overvoltage without interrupting power. Furthermore, it provides **in-rush current limiting** during power-up, preventing large current spikes that can cause system resets or damage.

A standout feature of this IC is its **extremely low quiescent current (IQ) of just 30µA**, making it exceptionally suitable for always-on applications and battery-powered systems where power conservation is paramount. This low IQ ensures that the protection circuit itself does not become a significant drain on the power source. The device also integrates comprehensive fault protection features, including **overcurrent protection (OCP)** and a timer-based fault latch-off mechanism. In the event of a sustained overload or short-circuit, the internal timer expires, shutting off the MOSFET to prevent thermal damage and safely disconnecting the load.

Housed in a compact DFN-8 package, the LTC4380IDD-2#PBF offers a high level of integration and is designed for ease of use in space-constrained applications. Its wide operating input voltage range of 4V to 72V, extendable to 100V with external components, makes it versatile for a broad spectrum of use cases, from automotive and industrial systems to telecommunications infrastructure and portable equipment.

**ICGOOODFIND**: The LTC4380IDD-2#PBF is an ideal, high-efficiency solution for engineers seeking non-destructive, robust overvoltage and overcurrent protection. Its combination of ultra-low quiescent current, precise linear regulation during transients, and comprehensive fault management makes it an indispensable component for enhancing system reliability.

**Keywords**: Surge Stopper, Low Quiescent Current, Overvoltage Protection, In-Rush Current Limiting, Fault Management