Littelfuse Introduces First Discrete Thyristor That Withstands Voltage Spikes Higher Than 1,200V

High voltage silicon controlled rectifier (SCR) switches in robust TO-218AC and TO-220AB packages
China, Beijing, March 1, 2016 — Littelfuse, Inc., the global leader in circuit protection, has introduced the company’s first discrete thyristor devices capable of withstanding voltage spikes higher than 1,200V. The Littelfuse Teccor brand SK225xD/SK255KD/SK625xD/SK655KD Series SCR Switching Thyristors are unidirectional switches designed to handle voltage spikes and power surges in incoming AC power mains. These SCRs can take up to 1,300V (SK225xD and SK255KD Series) or 1,700V (SK625xD and SK655KD Series) without malfunctioning. They are suitable for switching of 50/60Hz AC mains up to 440Vrms. These high voltage SCRs have high repetitive and non-repetitive peak off-stage voltage (VDRM/VDSM) ratings, ensuring reliable operation even when subjected to the high voltage surges common in commercial AC mains power in some areas.
Typical applications for the SK225xD/SK255KD/SK625xD/SK655KD Series SCR Switching Thyristors include AC solid-state switches, industrial power tools, and line rectification (50/60Hz). “These high voltage SCRs are ideal for use as unidirectional switches for AC mains power supplies up to 240Vrms that are subject to frequent voltage surges or mains voltage fluctuations, or up to 440Vrms in stable voltage,” said Daisy Wang, global product marketing manager, SCR switching thyristors. “They are particularly useful in regions where the AC mains voltage is unstable; even 240Vrms or lower lines may have voltage spikes of 1,000V or higher, so a 1,200V or 1,600V SCR may be required.”
SK225xD/SK255KD/SK625xD/SK655KD Series SCR Switching Thyristors offer these key benefits:
•  High repetitive peak off-state voltage (VDRM) of 1,200V or 1,600V ensures reliable operation for AC mains voltages of 440Vrms (SK225xD and SK255KD Series) or 600Vrms (SK625xD and SK655KD Series).
•  High non-repetitive peak off-state voltage (VDSM) of 1,300 or 1,700V means these devices can withstand voltage surges common in commercial AC mains power.
•  Durable internal ceramic insulation (RD, LD and KD packages) provides high electrical isolation voltage to ensure operating safety.
SK225xD and SK625xD Series SCR Switching Thyristors are available in TO-220AB packages and are sold in tube packs in quantities of 1,000. SK255KD and SK655KD Series are available in TO-218AC packages and are sold in tube packs in quantities of 450 (30 per tube). Sample requests can be placed through authorized Littelfuse distributors worldwide. For a listing of Littelfuse distributors, please visit
For More Information
Additional information is available on the Littelfuse Teccor brand SK225xD, SK255KD, SK625xD and SK655KD Series SCR Switching Thyristors product page. If you have technical questions, please contact: Koichiro Yoshimoto, thyristor business development manager,


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