Embedded applications requiring the smallest form factor memory storage design and needing high endurance, high reliability and/or long life cycles with locked BOM control should consider Industrial microSD cards.
The microSD standard was officially approved by the SD Association in July 2005, although it had been around prior to this under the names TransFlash and T-Flash. It has a very small physical size of 15.0 × 11.0 × 1.0mm and weighs ~0.25 gram.
As shown below, connectors for microSD are available from many vendors in many styles. Some are just surface mount parts with metal contacts. Others add a half or full frame. Depending on the application, there are push-push, eject switch and latching connectors as well. 5,000 to 10,000 insert and removal cycles are typical.
The Industrial Grade micro SD are based on SLC NAND memory and have extremely high endurance cycles. Industrial microSD are not common since most microSD cards are built strictly for cost in the consumer market. These consumer microSD cards are based on the lowest cost memory, which today is TLC (Tri-Level-Cell) NAND and have limited endurance of as little as 200 writes per physical block.
In addition to using the highest reliability SLC NAND die, Cactus locks the BOM on our Industrial microSD cards so the part that is sampled and qualified is the same as the part received in production. Combine this with our long life cycles and you have a product that will last over 5 years without any requirements for additional qualification.
Typically all SD and microSD products are rated at an operating temperature range of -25C to 85C regardless of the memory used. For extended temperature operations needing -45C to 90C, Cactus offers an extended temp Industrial microSD card. These are 100% tested for extended temp and guaranteed for a full life of operation, typically exceeding multiple decades in most applications.
From a performance point of view, Industrial microSD cards pack a lot in to a small form factor. While Industrial Grade microSD are more focused on longevity, BOM control and reliability, they are able to transfer data at up to 25MB/second. For handheld devices, this generally exceeds the highest requirements.
If you need any assistance designing an industrial microSD into your application, please feel free to contact a Cactus Expert for help.