New SD and Micro SD memory cards provide optimized performance balance

Swissbit has introduced a series of new SD and Micro SD memory cards for cost-sensitive applications that still require high reliability. Due to the innovative Swissbit firmware translation layer architecture (FTL), which is the world’s first implementation of a sub-page based firmware on SD cards, the new S-45 and S-45u offer several key features that cannot normally co-exist in an SD/Micro SD card.

These include:

1. Cost competitiveness due to MLC flash.
2. Extended endurance through reduction of the WAF (write amplification factor).
3. Increased retention time and elimination of read disturb through autonomous data refresh and background scan.
4. High sustained random write performance for small data size operations.
5. Power fail-safety by using a transaction log.

The sub-page based FTL reduces the internal management unit size by factors and speeds up the processing of small sector writes. SD memory cards are typically optimized for sequential writes, while random writes of small transfer sizes suffer from a massive degradation in performance. With the new FTL architecture, the S-45 offers a data rate for small sector random writes on average 50 to 100 times higher than comparable cards available on the market, which significantly accelerates the operation of embedded applications.

Hand in hand with this increase in random write performance goes a reduction of the WAF in the same magnitude. Users benefit from an endurance of the MLC flash that comes close to today’s SLC cards. The S-45/S-45u cards comply with UHS-I bus mode, up to speed class 10 and offer a sequential data rate with close to 38 MB/s.

The S-45 (SD) and S-45u (Micro SD) memory cards are equipped with intelligent read disturb management (RDM) alongside an autonomous, performance-neutral background 'auto-refresh' process. This type of data care management extends the data reliability, especially in read-intensive applications. Thanks to the sub-page based management the busy time is kept below the spec limit under all conditions, allowing a high sustained IOPS rate and guaranteeing compatibility with the most widespread industrial and networking SD applications.

Power fail safety is achieved by transaction log-based firmware and has been verified in the stringent Swissbit product qualification process utilizing fully asynchronous power-down cycles. Firmware upgrades can be performed both in the factory and in the field.

Diagnostic functions offering highly detailed status information plus standalone data maintenance guarantee data retention for many years, even in especially rough environmental conditions and in extreme temperatures. Users benefit from the shortest possible downtimes thanks to an extended operating life in the field and long data reliability.

Selected hardware, materials and production processes according to automotive standards ensure that the SD and Micro SD memory cards are of the highest quality. The high-performance controller offers the best ECC (error correction code) on the market.

The S-45 and S-45u series have been optimised for cost-sensitive SD memory card applications without compromising endurance. These cards are especially suited to read-intensive applications as well as a wide variety of industrial and networking general purpose usage. The S-45 SD memory cards with densities from 4 GB to 64 GB and S-45u Micro SD memory cards from 4 GB up to 16 GB will be available in Q3 2015. Depending on the project size, Swissbit is able to realise customer-specific modifications with virtually no limitations, says the company.