Electronika enterprises offers sidactors [telephone line protectors]. These are new generation of solid-state protection devices, which have fast response to spike in compared to conventional protection devices like gas discharge tubes [gdts] and metal oxide varistors [movs]. The product is a pnpn device that can be thought of as a tvs diode with a gate. Upon exceeding its peak off-state voltage [vdrm], the product will clamp a transient voltage within the devices switching voltage [vs] rating. Once the current flowing through the product exceeds its switching current, the device will crowbar and simulate a short circuit condition. Once the current flowing through the product is less than the devices holding current [ih], the product will reset and return to its high off-state impedance. Advantages of the product include: fast response time; stable electrical characteristics; long-term reliability and low capacitance. Because the product is a crowbar device, it cannot be damaged by voltage and it has extremely high surge current ratings. When protecting telecommunications circuits, the product is connected across tip and ring for metallic protection and across tip, ring and ground for longitudinal protection. The products are typically placed behind some type of current limiting device such as a slow blow fuse. Areas of application include central office line cards; t-1/e-1, isdn, and xdsl transmission equipment; customer premises equipment [cpe] such as phones, modems, and caller id adjunct boxes; pbxs, ksus and other switches; primary protection including main distribution frames, 5-pin modules, building entrance equipment and station protection modules; data lines and security systems; catv line amplifiers and power inserters; and sprinkler systems.
