Thyristor Surge Protectors Include Crowbar Action

A new family of surface-mount thyristor surge protectors called THYZORB provides clamping operations as well as bi-directional crowbar protection for a wide range of applications and designs. The devices' maximum breakover voltage ratings range from a low of 70V to a high of 395V with surge capabilities up to 100A. The devices differ from standard avalanche-type transient voltage suppressors by providing a crowbar action that allows switching from a high-impedance, high-voltage off-state to a low-impedance, low-voltage on-state. This permits redirecting current surges directly to ground. Devices in the plastic molded SMA packages have surge capabilities up to 50A. Devices in the larger SMB packages have capabilities up to 100A. Leakage current for all of the components is less than 50 nA, and minimum holding current is specified as 150 mA. Standoff voltages range from 55V to 320V. All types have UL Flammability Classification 94V-0 and have built-in strain relief for high reliability in surface mount applications. In addition, all devices available in the line promise to comply with all international regulatory standards and requirements. Pricing ranges from $0.14 to $0.24 each/10,000. For further information, and availability durations, contact VISHAY INTERTECHNOLOGY, Hauppauge, NY. (631) 300-3816.