MicroSD
MicroSD (styled "microSD") is a format for removable flash memory cards. SD is an abbreviation of Secure Digital. The cards are commonly used in cellular phones, as well as in some newer handheld GPS devices, portable media players, digital audio players, expandable USB flash memory drives, Nintendo DS flashcards, and digital cameras.
It is the smallest memory card available commercially; at 15 mm × 11 mm × 1 mm (about the size of a fingernail), it is about a quarter the size of a standard-sized SD card.[1] There are adapters which allow a microSD card to be used in devices intended for standard SD, miniSD, Memory Stick Duo and even USB cards. However, they are not universally compatible. Many microSD cards sold online and in stores are packaged with a standard SD adapter to use the card in devices that take standard SD but not microSD cards. TransFlash and microSD cards are the same (each can be used in devices made for the other), except that microSD adds support for SDIO mode, enabling non-memory cards like Bluetooth, GPS, and Near Field Communication devices.[2]
A point of confusion can come from the difference in the microSD and the newer microSDHC format. The SD and SDHC share a similar form factor, but not all devices are compatible with the newer high-capacity format. This is even true with devices that have been developed by SanDisk such as their e200 series of MP3 players. Using 3rd party firmware, however, SDHC reading capabilities can sometimes be possible.[3]
Older TransFlash cards are available in 16MB and 32MB format. MicroSD cards are currently available in capacities from 64 MB to 2 GB, while MicroSDHC cards are currently available in capacities from 4 GB to 64 GB. (This is the largest MicroSD card yet, and the limit of the MicroSDHC technology as well. MicroSD cards with larger capacities will be in MicroSDXC format.)
History
The microSD format was created by SanDisk. It was originally called T-Flash, and then TransFlash, before being renamed microSD when adopted by the SD Card Association (SDA). Other flash card formats approved by the SDA include miniSD and standard SD card.
The SDA announced the microSD format at CTIA Wireless 2005 on March 14, 2005, and approval of the final microSD specification was announced on July 13, 2005. At launch, the microSD format was available in capacities of 32, 64, and 128 MB. SanDisk introduced a 2 GB microSD card in July 2006, initially priced at $99 (USD). Since then, prices for flash memory devices have fallen dramatically. As of April 2009, the same 2 GB card could be found for as little as $12 (USD) at department stores, and as of May 2009 for as little as $6 (USD) at online electronics stores. In January 2010, a 16 GB micro SD card class 2 cost about $40 (USD), and a 4 GB class 2 micro SD card about $8 (USD).
It is expected that the SDXC (up to 2 terabytes data) format will eventually be carried over to the MicroSD cards;[citation needed] a timeframe or announcement has not been made.
Comparisons
Template:MultiMediaCard comparison
Power Consumption
The power consumption of microSD cards varies by manufacturer, but appears to be in the range of 20-100 mA at a supply voltage of 3.3 V. Specifications from TwinMos technologies list a maximum of 45 mA during transfer.[4] Toshiba, on the other hand, lists 80-100 mA.[5]
See also
References
- ^ "microSD Card". SD Card Association. Retrieved 2008-09-13.
- ^ microSD definition (Phone Scoop)
- ^ Rockbox change 2007-08-22: Added support for MicroSDHC cards on Sansa e200
- ^ http://www.twinmos.com.tw
- ^ http://www.toshiba-memory.com/en/micro_sd_cards.html
External links
| Main articles | .svg) | |
|---|---|---|
| Types |
| |