microSD From Wikipedia, the free encyclopedia
A microSD card next to its SD adapter Dissected 64 MB microSD Card, showing cross section through memory chips and printed circuit boardmicroSD is a format for removable flash memory cards. It is derived from SanDisk TransFlash and is used mainly in mobile telephones, but also in handheld GPS devices, portable audio players, video game consoles and expandable USB flash memory drives.
It is currently (2007) the smallest memory card available commercially. At 15mm × 11mm × 0.7mm (about the size of a fingernail), it is about a quarter the size of an SD card. There are adapters which allow a microSD card to be used in devices intended for SD, miniSD, or MemoryStick Duo cards, however they are not universally compatible.
TransFlash and microSD cards are the same (each can be used in devices made for the other), except that microSD devices can also support NFC (Near Field Communication).
As of October 2007, microSD cards are available in capacities from 64MB to 6GB (with 8GB announced but not yet available from retailers). Cards at and beyond 4GB are available only in the newer SDHC format developed both by KingMax and by SanDisk. These have a storage density of 34 GB/cm3.
On 27th June 2007, Toshiba announced a 4GB microSDHC card and Sandisk announced 6GB and 8GB MicroSD cards that were released in october 2007.
On 17th May 2007, Samsung announced that they had developed an 8GB (68 GB/cm3) MicroSD card. This exceeds the current capacity and write speed of microSD cards and can be written at 4MB/s or faster. "This is also much faster than the SD Speed Class 2 designation carried by most competing microSD cards currently on the market ." As this card was just recently developed, it is not available for commercial or personal purchase yet.