SD card
Secure Digital, officially abbreviated as SD, is a proprietary, non-volatile, flash memory card format the SD Association (SDA) developed for use in portable devices.
From top to bottom: SD, miniSD, microSD | |
Media type | Memory card |
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Capacity |
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Block size | Variable |
Read mechanism |
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Write mechanism | Variable |
Standard | SD Standard |
Developed by | SD Association |
Dimensions |
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Weight |
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Usage | Portable devices, such as digital cameras and mobile phones (including most smartphones) |
Extended from | MultiMediaCard |
Released | August 1999 |
The standard was introduced in August 1999 by SanDisk, Panasonic (Matsushita) and Toshiba as an improvement on MultiMediaCards (MMCs). SDs have become an industry standard. The three companies formed SD-3C, LLC, a company that licenses and enforces intellectual property (IP) rights associated with SD memory cards and SD host-and-ancillary products.
In January 2000, the companies formed the SD Association (SDA), a non-profit organization to create and promote SD Card standards. As of 2023, the SDA has approximately 1,000 member companies. It uses several SD-3C-owned trademarked logos to enforce compliance with its specifications and denote compatibility.