SD卡采用memory ic 制作，价格波动频繁，如果需要订货，请先跟我们联系，谢谢合作
SD卡在24mm×32mm×2.1mm的体积内结合了快闪记忆卡控制与MLC（Multilevel Cell）技术0.13u的NAND技术，通过9针的接口界面与专门的驱动器相连接，不需要额外的电源来保持其上记忆的信息。而且它是一体化固体介质，没有任何移动部分，所以不用担心机械运动的损坏。
SD卡的技术建是基于MultiMedia卡（MMC）格式上发展而来，大小和MMC差不多，尺寸为32mmx24mmx2.1mm.长宽和MMC一样，只是比MMC厚了0.7mm，以容纳更大容量的存贮单元。SD卡与MMC卡保持着向上兼容，也就是说，MMC可以被新的SD设备存取，兼容性则取决于应用软件，但SD卡却不可以被MMC设备存取。（SD卡外型采用了与MMC厚度一样的导轨式设计，以使SD设备可以适合MMC）。
SD接口除了保留MMC的7针外，还在两边加多了2针，作为数据线。采用了NAND型Flash Memory，基本上和SmartMedia的一样，平均数据传输率能达到2MB／s.
SD卡还提供不同的速度，它是按CD-ROM的150kB／秒为1倍速的速率计算方法来计算的。基本上，它们能够比标准CD-ROM的传输速度快6倍（900 kB／秒），而高速的SD卡更能传输66x（10 MB／秒）以及133x或更高的速度。一些数码相机需要高速SD卡来更流畅地拍摄影片，和连续拍摄相片更迅速。直至2005年12月，大部分设备跟从SD卡的1.01规格，而更高速至133x的设备亦跟从1.1规格。
设有SD卡插槽的设备能够使用较簿身的MMC卡，但是标准的SD卡却不能插入到MMC卡插槽。SD卡能够于CF卡和PCMCIA卡上，插上转接器使用；而miniSD卡和microSD卡亦能插上转接器于SD卡插槽使用。一些USB连接器能够插上SD卡，而且一些读卡器亦能够插上SD卡，并由许多连接埠，例如USB、FireWire等存取使用。
SD卡的结构能保证数字文件传送的安全性，也很容易重新格式化，所以有着广泛的应用领域，音乐、电影、新闻等多媒体文件都可以方便地保存到SD卡中。因此不少数码相机也开始支持SD卡。
SD卡应用于以下的手提数码装置：
●数码相机储存相片及短片
●数码摄录机储存相片及短片
●个人数码助理（PDA）储存各类资料
●手提电话储存相片、铃声、音乐、短片等资料
●多媒体播放器。
SD卡多用于MP3随身听、数码摄像机、数码相机等，也有用于笔记本电脑上。其投影面积与MMC卡相同，只是略微厚一点，为2.1mm，但是SD卡的容量大得多，且读写速度也MMC卡快4倍。同时，SD卡的接口与MMC卡是兼容的，支持SD卡的接口大多支持MMC卡。目前SD卡在数码相机中正在迅速普及，大有成为主流之势。SD卡在今年的发展很快，已经开始威胁到CF卡的市场分额了。这是由于SD卡的体积要比CF卡小很多，并且SD卡在容量、性能和价格上和CF卡的差距越来越小，而这两年支持SD卡的手机迅速在市场走热，因此，SD卡的迅速成长绝对不是偶然的。最重要的一点就是MMC卡也能和SD卡相兼容，这也正是SD卡迅速走红的原因之一。不过注意的是，在某些产品例如手机上，SD卡和MMS卡是不能兼容的。现在的SD卡容量由8MB到32GB不等。
SD card 24mm × 32mm × 2.1mm with a flash memory card inside the volume control and MLC (Multilevel Cell) NAND technology 0.13u of technology, through 9-pin interface and the interface is connected to a dedicated drive, no additional power supply to maintain the information on the memory. And it is the integration of solid medium, without any moving parts, so do not worry about damage to mechanical motion.
SD card technology built is based on the MultiMedia Card (MMC) format, developed from, size, and MMC similar size 32mmx24mmx2.1mm. The same length and width, and MMC, but MMC thicker than 0.7mm, to accommodate the larger capacity storage storage unit. SD card and MMC card to maintain upward compatibility, ie, MMC SD devices that can be a new access, compatibility depends on the application, but the SD card, MMC devices but can not be accessed. (SD cards and MMC form factor using the same thickness of rail design to enable the SD device can be suitable for MMC).
SD MMC interface, in addition to the 7-pin external reserves, also adds a 2-pin on both sides, as the data line. Using NAND-type Flash Memory, SmartMedia essentially the same as the average data transfer rate can reach 2MB / s.
SD card also provides a different speed, which is based on CD-ROM, 150kB / s rate of speed as a method to calculate. Basically, they will be better than the standard CD-ROM 6 times faster transmission speed (900 kB / sec), while the more high-speed SD card transfer 66x (10 MB / sec), and the speed of 133x or higher. Some digital cameras require high-speed SD card to shoot video more smoothly and faster continuous shooting photos. Until December 2005, most of the equipment to follow SD card specification 1.01, while the higher speed to 133x devices also follow the 1.1 specification.
The device has a SD card slot can use the MMC card than the book itself, but the standard SD card but can not be inserted into the MMC card slot. SD card to the CF card and PCMCIA cards, plug in the adapter to use; the miniSD card and microSD card can also plug in the adapter in the SD card slot. Some USB connector to plug in the SD card, and some readers will be able to plug in the SD card by the number of ports, such as USB, FireWire and other access to use.
SD card structure can guarantee the security of digital file transfer, and very easy to reformat, so have a wide range of applications, music, movies, news and other multimedia files can be easily saved to the SD card. So many digital cameras have begun to support the SD card.
SD card used in mobile digital devices the following:
● digital cameras store photos and video clips
● Digital video cameras store photos and video clips
● Personal Digital Assistant (PDA) various types of information stored
● mobile phone store photos, ring tones, music, video, etc.
● multimedia player.
SD card is used for MP3 music players, digital cameras, digital cameras, they are also used in notebook computers. The MMC card with the same projected area, only slightly thicker, as the 2.1mm, but the much larger capacity SD card and MMC card read and write speed is 4 times faster. At the same time, SD card interface is compatible with the MMC card, SD card, MMC card interface for most of the support. SD card is currently being in the rapidly growing popularity of digital cameras, much as the mainstream trend. SD card in this year's rapid development has begun to threaten the CF card's market share was. This is due to the size of SD card is much smaller than the CF card and SD card capacity, performance and price and growing gap between the small CF card, SD card, which two years of phone support to market quickly take the heat, so , SD card, the rapid growth is definitely not accidental. The most important point is that MMC cards and SD cards can be compatible, which is the SD card quickly became one of the reasons. But note that in certain products such as mobile phones, SD cards and MMS card is not compatible. Now the SD card capacity from 8MB to 32GB range.
