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2018.05.15 - SSDI Adds Surface Mount Options to SCR Replacement

7 Amp, 400 Volt SCRs

SSDI is proud to introduce new surface mount package options for 7 amp, 50 – 400 V Silicon Controlled Rectifiers. Customer interest in SCRs has increased as these products have become more difficult to find. SSDI was able to develop a drop-in replacement in a standard TO-5 package that a customer had difficulty procuring. To facilitate efficient PCB design and mounting, SSDI also offers hermetic, surface mount options in the SMD.5 and Cerpack packages.

While the drop-in replacement has a max rating of 50 volts, SSDI’s SFS07050 - SFS07400 series of SCRs offers an extended voltage range up to 400 volts. These hermetic devices can be used in high reliability applications such as AC power control, AC power switching, and overvoltage protection in crowbar circuits. With the increased voltage range, these SCRs are ideal for switching applications involving high voltages. The SFS07XXX family also has low-level gate characteristics such as a low holding current of 1.25 mA (typ) at 25°C and gate trigger current of 20 µA (typ).

For over 40 years, SSDI has supplied hermetically sealed silicon controlled rectifiers (SCRs) and programmable unijunction transistors (PUTs) to the aerospace and defense industries. SSDI has employed its engineering / design expertise to supply thyristors with enhanced electrical performance such as higher current products and faster tq versions of standard industry products. While typically supplying devices up to 55 amps and 1,000 volts, SSDI has begun offering thyristor products from less than 1 amp to over 175 amps as well as up to 1,600 volts. Whether searching for higher current, faster tq, or smaller / modern packaging options, design engineers are no longer limited to the thyristor product offering of the past. SSDI continues to offer a wide range of innovative, high reliability solutions and enhanced screening options to meet or exceed its customers’ specific program needs.

Contact SSDI online or call (562) 404-4474 to request samples or discuss specific program requirements.


  • Low-Level Gate Characteristics
  • IGT = 20 μA (typical) @ 25°C
  • Low Holding Current IH = 1.25 mA (typ) @ 25°C
  • Anode Common to Case
  • Hermetically Sealed

Refer to data sheet for ratings and case outlines

Visit the SCRs Product Category (PRODUCTS > Thyristors > SCRs) to view additional hermetic Silicon Controlled Rectifiers

SSDI's Thyristors Catalog is also available for download at SUPPORT > Literature