354A FET Cycling Control TM

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Intelligent Instrumentation for Power TM

Please Note: By unanimous consent of partners, Wyeast Technology, LLC was dissolved on December 31, 2005. Support for existing customers and products may be availiable on a case-by-case basis. If you have a 354A in need of service, please contact Alex Faveluke. It is my goal to keep customers satisfied.

Picture of 354A FET Cycling Control. Fits nice in a rack. Bigger than a breadbox.


The 354A controls power cycling, recording fine grained data extremely useful for die attach, package, and thermal interface evaluation.

The Need for Power Cycling

Power semiconductors are showing up in more products every day, providing new features and energy efficiency. One of the inherent challenges in any product design is to add features and efficiency while maintaining reliability over desired operating life. This is especially true when applying power electronics, given large thermal stresses on high power, large silicon area parts.

Large semiconductor devices wear out at end of life due to thermal cycling. As a part heats and cools, stresses develop due to differences in material thermal expansion coefficients. These stresses degrade package interface materials, leading to reduced performance as the part ages. Power cycle testing is used to evaluate the effect of this repetitive stress in a manageable time period.

354A FET Cycling Control TM

The 354A FET Cycling Control regulates and measures heating power to MOSFET devices under test. Junction temperatures are measured before and after each and every heating cycle. A host computer system provides a convenient graphical user interface and logs all data to a powerful, flexible database. The tight control over in-situ junction temperatures and comprehensive data logging combine to provide a continuous view of thermal degradation over cycle testing.

Advantages and Capabilities of the 354A

  • Fine grained automatic control of heat power prevents DUT runaway into destruction.
  • Data logging capabilities show a continuous picture of DUT aging.
  • Capability to cycle from 2 to 8 DUTs in same test provides increased sample size or ability to quickly compare differences in construction or mounting.
  • Continuous monitoring of start temperature terminates testing if cooling system takes a vacation.
  • Part characterization (k-factor) is easy with GUI control.
  • Comprehensive report generation routine generates spreadsheet readable file, eliminating the need for user database programming.
  • Automatic control of heat power eliminates constant interaction and manual adjustment of power cycle testing.

Please See 354A Brochure for more information

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