Developers

Home » Developers » SD Technology

SD Technology Overview

Capturing the World at the Speed of Life

SD memory cards are an innovative, always evolving bridge media powering the future of the digital world. SD memory cards deliver high-performance products that allow consumers to quickly capture video, photos, and sound in a reliable, easy-to-use format.

SD technology is the de-facto industry standard for mobile phones, digital cameras, MP3 music players, personal computers, printers, car navigation systems, electronic books, and other consumer electronic devices. SD technology is used in some 400 products across dozens of product categories and in more than 8,000 models.

SD memory cards are available in standard and high-capacity formats along with a variety of speed classes. The cards have the broad interoperability and compatibility needed to ensure that its applications will continue to expand far into the future.

High-Capacity Cards: The SD Standard Grows

SD and SDHC memory card compatibility

The SD Association established a new specification rating for the minimum data transfer for standard and high-capacity cards, as well as both types of host products. With the ability to store between 4GB to 32 GB, you can do more at faster speeds across the entire SD line. Every high-capacity card is noted with “HC” to clearly designate this new capability.

With more storage, comes the need for faster speeds. The three new Speed Classes allow host products to check the fragmented state in a card and calculate the write speed in each part of the card. This lets the host quickly determine where to write the data according to its speed requirement. The three SDHC speed classes — Class 2, Class 4 and Class 6 — transfer data at least 2, 4 and 6 MB per second, helping you to guarantee performance of your products.

Copyright Protection

Ready for the Secured Digital Content

Content Protection for Recordable Media (CPRM), the content protection technology used for the SD card, is key to enabling a new distribution system for music and other commercial media. CPRM assures a high level of protection against illegal copying. The technology was developed by the 4C Entity, LLC (The digital contents copyright protection technology licensing organization of IBM, Intel, Panasonic, and Toshiba.)

Having a proven record in DVD, this protection is enhanced in SD memory cards through the use of "key revocation" technology built into each card.

The card's control circuitry allows data to be read and written (in its protection area) only when appropriate external devices are detected. A check-out (copying) from a PC to the SD memory card is restricted to three copies in compliance with the SDMI specification. All SD-Audio products comply with SDMI.

The SD card copyright protection function has the following features:

  • Access to an SD memory card must be enabled by authentication between devices
  • A random number is generated each time there is mutual authentication and exchange of security information

Standard Formats

  SD miniSD microSD
Size SD Card SD Card SD Card
Area 768 mm2 (100) 430 mm2 165 mm2
Card Volume 1,613 mm3 (100) 602 mm3 165 mm3
Thickness 2.1 mm 1.4 mm 1.0 mm
Weight Approx. 2g Approx. 1g Approx. 0.5g
Number of pins 9 pins 11 pins 8 pins
File System FAT16/32 FAT16/32 FAT16/32
Operating Voltage 2.7V - 3.6V 2.7V - 3.6V 2.7V - 3.6V
Write-protect Switch YES NO NO
Copyright protection CPRM CPRM CPRM
Compatibility - Yes (with adapter) Yes (with adapter)
Capacity Up to 2 GB Up to 2 GB Up to 2 GB

High-Capacity Formats

  SDHC miniSDHC microSDHC
Size SD Card SD Card SD Card
Area 768 mm2 (100) 430 mm2 165 mm2
Card Volume 1,613 mm3 (100) 602 mm3 165 mm3
Thickness 2.1 mm 1.4 mm 1.0 mm
Weight Approx. 2g Approx. 1g Approx. 0.5g
Number of pins 9 pins 11 pins 8 pins
File System FAT32 FAT32 FAT32
Operating Voltage 2.7V - 3.6V 2.7V - 3.6V 2.7V - 3.6V
Write-protect Switch YES NO NO
Copyright protection CPRM CPRM CPRM
Compatibility - Yes (with adapter) Yes (with adapter)
Capacity 4 - 32 GB 4 - 32 GB 4 - 32 GB

SD Memory Card Family Index