Why pay more money for something you don’t need? It’s obvious you shouldn’t. So the purpose of this article is to point out the reasons an OEM Embedded Systems designer would NEED Industrial Grade Flash Storage in their system.
If you look at the home page of our Cactus website, you will see our tagline, “Manufacturing the world’s most reliable Industrial Grade Flash Storage Devices for applications where failure is not an option.” In a nutshell, that’s it.
If your OEM design requires reliability and failure would be catastrophic, extremely costly or severely damage your company’s reputation, then that is an application worthy of the added expenses of Industrial Grade. These can come in forms such as SLC CFast, SLC SD Card and SLC microSD Cards.
Now let’s define what goes into Industrial Grade Flash products.
The first and most important part of an Industrial Grade device is the flash memory. If NAND memory with limited write endurance or reliability is used, it is not INDUSTRIAL Grade.
There are manufacturer’s claiming Pseudo-SLC, and MLC NAND based products are Industrial Grade. Beware, they are not!! These are attempts to fit a lower reliability product into Industrial applications which need SLC NAND. They are made with finer trace widths, have more pronounced adjacent cell cross-talk issues and are more susceptible to unexpected power loss and temperatures than SLC NAND.
This is why Industrial Grade parts are made with SLC NAND Flash memory from one of only a small number of flash manufacturers who have volume sufficient to ensure quality. In fact, the older the semiconductor process, the more reliable the parts. Today many Cactus products are still made using 43nm SLC NAND which was introduced last decade. These provide great Data Retention for >10 years.
Next up is the Industrial Controller and Firmware Algorithms. A truly Industrial Grade product uses a controller which is designed from the ground up for reliability over cost, performance or other attributes.
These controllers are generally not the first to market, but once they are launched, they are built identically and contain the same firmware for each build. Presumed simple controller silicon and firmware changes can introduce a latent defect which can rear its ugly head at the worst moment. A thorough qualification of the Industrial Grade device in the OEM systems and then a Locked-BOM, including firmware is the best way to prevent introduction of bugs into a system design.
Changing the BOM (Bill-Of-Material), or the parts contained inside the flash storage device, is the way most flash storage suppliers keep their costs down. It allows them to use the lowest cost memory, controller or other components available at the moment. True Industrial Grade parts have very Long Life Cycles and do not change the BOM.
In the rare instances when a change in the BOM is required, a true Industrial Grade Flash Storage supplier provides a PCN (Product Change Notification) which explains the change in the BOM, why the change is necessary and gives several months to qualify the change with an additional several months to continue purchasing the current part.
In situations where the cost of a qualification on a legacy design makes no sense, Cactus can and does extend the life by months or in some cases years based on the OEMs needs.
There are a number of other items such as SMART Product Life Prediction data reporting, Unexpected Power Interrupt Handling, limited use of DRAM cache and Wide Temperature Range operation.
First, define the exact requirements of the OEM system. Many designers assume all flash cards are created equal. Most of the consumer flash devices do not publish their endurance cycles and other than, “Oh, it should work fine in your system,” do not have much support.
With a well-defined usage requirement of the flash storage device, the designer can make the right choice of product.
If you would like assistance in this decision making process, contact us for more information.