BEWARE - MLC NAND Memory Transition coming to Flash Card Near You

In the semiconductor world, a die shrink signifies less silicon is needed to get the same or more powerful component and therefore a lower cost to the market. This process repeats itself year after year and is an enabler to bring down the cost.

This shrinking process ties in with Moore’s Law, an observation by Gordon Moore in 1965 that describes a doubling of the number of components per integrated circuit ever year. A decade later he revised this to a doubling every two years.

NAND Flash memory has enjoyed this same increase in memory capacity per die for decades since invented by Toshiba in 1987.

While the latest generation of NAND flash brings higher capacity and performance at a lower cost, it also can bring some challenges such as lower endurance cycles, higher error rates and cell to cell coupling effects which bring down reliability.

To compensate for this lower reliability of the NAND itself, more sophisticated NAND controllers are used with higher ECC and better algorithms to minimize the latest NAND deficiencies. These controllers introduce new firmware, timing and other functions which may lead to compatibility issues in existing OEM systems.

Transition from 19/20nm MLC to 15/16nm MLC NAND

The most recent transition in the market is happening now with the MLC NAND. Many flash card suppliers are quickly making the move from the 19 & 20nm generation to the 15 & 16nm generation.

Unlike Cactus Technologies, with MLC NAND flash products most suppliers tend to transition without notification to the customer. This creates an issue since the new 15/16nm MLC NAND has not been thoroughly tested and qualified in the OEM’s host system. The first time they may experience an issue would be on the arrival of the new generation parts in production.

Without a thorough qualification, an even more serious issue that can arise is the newer generation not having the same number of endurance cycles as the previous generation. At a minimum a calculation should be made to ensure the latest memory can meet the applications lifetime demands. The best case is for a full qualification with an accelerated life test to be performed prior to shipping to customers.

Cactus lives and breathes Industrial Grade flash storage products, based on the highest reliability SLC NAND flash as well as a thoroughly tested, locked-BOM, Commercial Grade offering based on the more cost effective MLC NAND.

Embedded and Industrial OEM designers are encouraged to contact us for assistance with the memory design for their system.

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 Google+