SA170

TVS (transient voltage suppressor) diodes are protective devices designed to provide protection for electrical systems against the potentially damaging transient voltages that can be caused by electrostatic discharge (ESD), lightning, and other fast transients. The SA170 is a type of such device that incorporates a reverse-biased Zener diode along with an ignitron tube in order to offer protection against both high and low voltage events.

At its core, the SA170 operates on the principle of silicon avalanche. When a reverse-biased Zener diode is subjected to a voltage greater than its breakdown voltage, it is capable of undergoing a process known as the avalanche effect. This process is characterized by a sudden release of a large amount of current that is hundreds of times larger than the device\'s normal operating current, and can be used to trigger the ignitron tube, which is connected in series with the Zener diode. The sudden switching of the ignitron circuit creates a so-called “flyback” voltage that can clamp the peaks of transients or spikes, and thus provide overvoltage protection for the system.

The SA170 is especially well suited for ESD and lightning protection in applications that operate at relatively low voltages, such as aircraft avionics and navigation systems. The high capacitance of the SA170 gives it a low On-state resistance, making it ideal for power system applications. The device also offers significant ESD protection with a clamping ratio of greater than 13:1, making it a strong choice for protecting critical components.

In addition to excellent transient overvoltage protection, the SA170 is also capable of providing isolation. When the ignitron tube is triggered, it very quickly shorts out the two terminals of the device, providing electrical isolation between them and helping to minimize the risk of arcing and electrical damage. This makes the SA170 an ideal choice for applications that require isolation in addition to ESD/transient protection.

All in all, the SA170 is an incredibly useful and versatile device for operation in the most extreme environmental conditions. It’s capable of protecting delicate electronics and other systems against ESD, lightning, and other transients, and its built-in isolation capability provides even greater system protection. This makes it a great choice for any application requiring ultra-reliable protection in a variety of environments.