An SD card device is a secure digital non-volatile memory card. The SD card is used in electronic devices, such as media players, cell phones, digital cameras and video games. A regular SD card capacity usually ranges from 4 MB to 4 GB. A higher capacity SD card ranges from 4 GB to 32 GB. The following provides more information about SD card devices.

History

In the year 1999, the first SD card device created had a size of 24 mm x 32 mm x 2.1mm. The card provided DRM. This new card format at the time was made to compete with a card that was released one year before by Sony's Memory Stick format, "MagicGate" DRM. In the year 2000, samples of the first SD memory cards were available to you with 32 and 64 megabytes.

Design

SD card devices are asymmetrically shaped. Most SD cards have a thick design of 32 mm x 24 mm x 2.1 mm. If your SD card is missing a write-protect switch, you have a thinner card, "Thin SD." SD cards contain recessed electrical contacts to protect these from your Fingers. Most SD memory cards contain a transfer rate of 10 to 20 MB per second.

DRM Features

DRM stands for digital rights management, which is placed in the SD card devices. The DRM signifies that the device for recording media is protected. DRM is only available to licensees.

File System

SD memory cards come preformatted with a file system, FAT or FAT 32. You can use FAT ScanDisk utility to fix corrupted data. SD cards not larger than 4 GB can be formatted to a file system FAT 16 or FAT 32. You can format cards larger than 8 GB with file system, FAT 32.

Speeds

SD memory cards come in various speeds. Your standard SD card transfers data six times the data rate of a CD-ROM, which speed is 150 KB per second. Cards with higher speeds, such as the Micro SDXC card contain higher transfer rates of sixty-six times the standard transfer rates. Digital cameras contain higher write speed cards to enable you to record videos, and take multiple photos.

Types of SD Cards

Micro SD is a small memory card used in media players, audio players, digital cameras, and cell phones. A micro SD size is 15 mm x 11 mm x 1 mm. The micro card is used with an adapter to allow you to use the card in other devices, such as mini SD, USB cards and memory stick duo. The SD card uses byte-addressing, which allows for standard capacities. You can find the micro SD card available in 64 MB to 16 GB capacities.

The Micro SDHC card device is a secure digital high capacity flash memory card. The SDHC is the extended version of the SD standard. SDHC uses sector-addressing, which allows for higher capacities. Micro SDHC card has a higher capacity that ranges from 4 GB to 32 GB. The micro SDHC is not compatible with much older devices. The older devices can't read the SDHC format.

A Mini SD is another among the many different types of SD card devices. The mini SD is a portable compact memory card. This mini card is a smaller version of the standard SD memory card. The size of a mini SD is 21.5 mm x 20 mm x 1.4 mm. This memory card is used in digital cameras, MP3 players and cell phones. You can find a mini SD with a DRM of 2 GiB.

SDIO translates into secure digital input output. The Micro SDIO memory card is compatible with the SD card. The SDIO card's supported devices can use some devices that are used for the SD standard form. The devices that you can use are for example, Wi-Fi and ethernet adapters, TV tuners, digital cameras, and modems.

The Micro SDXC is another among the different types of SD card devices. SDXC is translated into secure digital extended capacity, which contains a higher capacity of 32 GB. Older devices may not be compatible with this extended version.

Sources:

http://en.wikipedia.org/wiki/Mini_SD

http://en.wikipedia.org/wiki/MicroSD

http://en.wikipedia.org/wiki/Secure_Digital_card

http://en.wikipedia.org/wiki/SDHC_Card#SDHC