What is tSD, qSD, and What is CS SD NAND ?

Recently, in a communication with my partner, someone mentioned the previous tSD and qSD products. My colleagues, as experienced participants in flash industry, are amazing that there are some guys still remember such kind of products.

And then what’s tSD and qSD ? Let me explain here briefly.

The constructure of tSD and qSD is controller + TLC NAND Flash. This kind of constructure make users quickly benefit TLC low cost (8 years ago).

tSD and qSD adopt BGA and TSOP. So we also called tSD/qSD SD card and TF card which packed by TSOP and BAG.

The main capacity is 8GB and 16GB for tSD and qSD. But these two products disappear from the market due to kind of reasons. Now CS SD NAND also called on board TF card,, on board SD card. tSD, qSD and CS SD NAND have the same constructure, inside are controller and NAND flash, outside are SD interface.

So What’s the differences from CS NAND and tSD, qSD ?

Flash inside is different. CS SD NAND adopt SLC NAND flash, the P/E-Cycle of SLC NAND can reach 100 thousand times. tSD, qSD use TLC NAND flash, the P/E-Cycle of TLC NAND just can reach 500-1000 times.

Capacity is different. The main capacity of CS SD NAND is 128MB/512MB, but the capacity of tSD/qSD is 8GB and 16GB.

Size and package technology are different. CS SD NAND use 6*8m LGA-8 package technology, small in size and easy for welding. Usually, tSD/qSD adopt two kind of package, BGA 153 balls, the size is 11.5 * 13 mm. Another is TSOP 48, 12*20mm.

Stability. The controller of CS SD NAND is the newest, and adopt SLC NAND. The tSD/qSD adopt TLC NAND Flash, which is only suitable for consumer who are sensitive to the price.

From the left to right：CS SD NAND, TF card，eMMC，SOP48(tSD/Qsd)

If you have any questions, please contact us

Email：line@longsto.com