TVSdiodi

TVS diodes, or transient voltage suppression diodes, are semiconductor devices designed to protect electrical circuits from short, high-energy voltage spikes such as electrostatic discharge (ESD), inductive switching transients, and lightning-induced surges. They remain nonconductive under normal operation and avalanche into a low-impedance state when a transient pushes the voltage beyond their threshold, clamping the voltage to a safe level for nearby components.

There are two main configurations: unidirectional and bidirectional. Unidirectional TVS diodes resemble a standard diode with breakdown in reverse, conducting mainly in one polarity and providing protection on a single supply rail. Bidirectional TVS diodes conduct in both polarities and are used on AC lines or data interfaces where transients can occur in either direction.

Typical usage involves placing the device in parallel with the protected path—across power rails, between signal lines and ground, or across interfaces such as USB, HDMI, or CAN buses. Key specifications include the stand-off voltage (Vrwm), the breakdown voltage (Vbr), the clamping voltage (Vcl), peak pulse current (Ipp), and the capacitance. Designers also consider leakage current, packaging, and thermal behavior.

Applications span consumer electronics, automotive and industrial equipment, networking gear, and data interfaces, where rapid response and reliable protection are crucial. TVS diodes are often chosen to complement other protection devices (such as fuses and MOVs) and are selected so the clamping voltage remains below the voltage rating of protected components while handling the expected surge energy.

Compared with MOVs, TVS diodes offer faster response and tighter clamping, making them well-suited for protecting sensitive electronics against fast transients, while MOVs may be used for higher-energy, slower surges.