The digital imaging chip that just won’t quit

TI AvatarMike Douglass oversees a frenzy of digital micromirror device (DMD) abuse at our DLP® products qualification and development testing laboratory in Dallas – and it’s all on purpose. Amid electrical hums, whirs and clicks of testing bays and workstations, DMDs are routinely put through conditions beyond anything the “real” world can offer.

One area jolts DMDs with electricity to test their physical endurance (DMDs, after all, are a class of – take a deep breath and say it slowly –microelectromechanical systems (MEMS)). Across the hall, in what looks like a meat locker, chips are chilled to a brisk minus 67 degrees Fahrenheit. Another rack of specialized ovens roasts the chips at 257 degrees Fahrenheit for weeks at a time. A device called the Mirror Master, meanwhile, scans the microscopic surface of every DMD, looking for microscopic flaws.

In all his years of trying to break things, one test has exceeded even the most ambitious expectations. In a nondescript corner of a workroom brimming with oscilloscopes, computer racks and testing equipment, a small batch of the first DMDs our company ever put into production has been tested continuously since Dec. 7, 1995.

“I wanted to see how long it would take for them to wear out and break,” Mike said of the nine DMDs now approaching 20 years of continuous operation. “I’m still waiting.”

The enduring DMDs represent our first generation of DLP® chips. Each has about 500,000 microscopic mirrors that flip thousands of times per second to reflect light when voltage is applied. By comparison, today’s advanced DLP solutions may include DMDs each containing tens of millions of micromirrors, and can display much higher resolutions.

Mike and his team perform intentional, deliberate torture on DMDs, day in and day out, to ensure reliability for a diverse range of applications ranging from movie theatre projectors and automotive head-up displays (HUDs) to 3-D printers and spectrometers.

“The job of our team here is to break things. We’re here to eliminate failures before they become failures,” Mike said. “If we can’t break it, that’s good.”

When coupled with a light source such as a color wheel, LED or laser, the micromirrors perform an orchestrated dance of precision, creating full motion images rich with color and detail suitable for many applications – on just about any surface.

TI Avatar“These original nine chips represent the moment we all realized we had an opportunity to make a business out of this,” Mike said. “Up until this design, we were stuck in the development phase. We did not see a path forward. These chips were our ‘aha’ moment.”

Over the years, the nine DMDs remained on the same testing board. For a time, Mike admits he even forgot he had put them up for testing. He rediscovered them a few months later. They still worked.

Months and years went by. The chips kept going. At years 13, 16 and 18, the team held parties to commemorate these milestones. In what has become something of an annual tradition, Mike sends his team an email with a status report on the DMDs.

As of last year, here are the numbers:

  • 161,000 hours of continuous operation at 149 degrees Fahrenheit.
  • 8.5 trillion mirror landings/cycles for each micromirror
  • 38 quintillion mechanical movements for all nine DMDs

These days, some new TIers may actually be younger than the chips.

“These chips are more robust than anyone expected,” Mike said. “I expect they will still be running after I retire, too.”

It’s important to note the performance of these DMDs is not representative of all DMDs placed into products, but celebrating this milestone each year has become a great way to recognize the original achievement and marvel at the stamina of these 9 chips.