Why Isn't my Flash Card Working in my Industrial Application?

If you don’t live and breathe flash storage, you may not be aware of the memory characteristics inside your SSD or flash card. At first glance it doesn’t seem very important, but the memory type greatly impacts the reliability of the overall flash storage device.

Flash Storage devices include flash cards such as CompactFlash, SD, microSD and PC Cards; flash modules such as mSATA and Slim SATA; and Solid State Drives in the 2.5” and 1.8” form factor. They are almost all designed and manufactured using NAND flash memory.

Generally that’s more than enough knowledge needed to make decision about which flash card to use in your mobile phone or camera. But, if you are designing a flash storage device into an Industrial, Medical or other OEM design which requires reliability, long life cycles, consistency of components, ruggedness and other characteristics, it helps to understand what’s under the hood…

Many of our best customers came to us with an issue caused by the wrong type of flash card in their application. Below I list a couple questions I was recently asked.

Aren’t All SD Cards the same?

Well, not really. The vast majority of the SD Cards on the market today are based on TLC (Tri Level Cell) NAND flash memory. While it is a very cool technology which stores 3 bits in each memory cell, it is also much more susceptible to a number of failure modes such as data corruption, adjacent cell cross coupling and it lacks sufficient endurance cycles to write much more data than required by a medium duty consumer application.

The “gold standard” of NAND memory is SLC (Single Level Cell). It is the oldest technology and simplest – storing just one bit per cell. But before you kick it to the curb, it is also the most reliable, longest life cycle and least susceptible to data corruption. SLC has a proven track record operating in extreme environments, heavy duty cycles and wide temperature ranges for decades. For Industrial OEM designs I would highly recommend using Industrial Grade SD Cards.

Do all Flash Card Controllers have the same Reliability?

Short answer, no. Flash card controllers are the intelligence between the NAND memory and the card’s interface to the host system. Different applications demand different characteristics. A consumer application demands lowest cost and in some cases performance.

For Industrial and embedded OEM applications, a controller that is first a foremost designed for reliability is the best answer. Whenever a compromise is needed during a design, the Industrial controller design engineer favors reliability.

The focus of Cactus Technologies has been Industrial Grade Flash Storage products since our inception in 2005. We are proud of our high quality products and would like to work with you on your Industrial or Embedded OEM application. If you would like more information, please contact us.

Steve Larrivee has over 30 year's experience in the data storage market, including 5 years at Seagate Technology and 10 years at SanDisk. He joined Cactus Technologies Limited as an equity partner and Co-Founded Cactus USA in 2007 with partner Tom Aguillon. Learn more about Steve on LinkedIn.