Secure Digital Card Pinout, SD Flash Card Memory Module Pin Out

Secure Digital Card Pinout

Secure Digital Card, Pin Out

Secure Digital [SD] is a flash based removable memory card. The card format may also be used other device functions in addition to data storage.
Secure Digital uses a 9-Pin connector [1 rows of 9 pins]. A compatible card format is called Secure Digital I/O [SDIO]. Refer to the SDIO page for information on that card standard.
Also refer to the microSD Card, or the miniSD Card pages.

SDXC memory card format; XC - for 'eXtended Capacity'
Refer here for the SD Association ... http://www.sdcard.org/developers/tech/sdhc/
The format used Microsoft's exFAT [FAT 64] file system. exFAT was introduced with Windows CE 6.0, and appeared in Vista in Service Pack 1.
Read and Write speeds to 104MB/s with 2TB capacity.
SDIO and SDHC, may be updated to support the higher data throughput.

SD Card

The Secure Digital card dimensions are: 24mm wide x 32mm long. The standard width is 2.1mm, while the Thin SD Memory Card has a width 1.4mm.

**Secure Digital Pinout**
Pin #	Pin Name	SD Signal Function SD Mode	SPI Signal Function SPI Mode
1	DAT3/CS	Data Line 3	Chip Select/Slave Select [SS]
2	CMD/DI	Command Line	Master Out/Slave In [MOSI]
3	VSS1	Ground	Ground
4	Vdd	Voltage Supply [2.7v or 3.6v]	Voltage Supply [2.7v or 3.6v]
5	Clock	Clock	Clock [SCK]
6	Vss2	Ground	Ground
7	DAT0/D0	Data Line 0	Master In Slave Out [MISO]
8	DAT1/IRQ	Data Line 1	Unused or IRQ
9	DAT2/NC	Data Line 2	Unused

The graphic below provides a comparison of the different Removable memory Card standards. Many of the different Memory Card standards have descriptions listed on this web site. The different standards based on card size are provided. Refer to the Personal Computer Buses page for more information for different memory types, as listed here.

Comparison of Flash Memory Card sizes

Refer to this page for a list of different Flash Memory Stick Formats.

The graphic to the right shows:
The SD card, 32mm x 24mm
The miniSD card, 21.5 x 20mm
The microSD card, 15mm x 11mm

Note that pin contacts 3 and pin 4
are bit bit longer than the other pins.
This allows pin 3 [Vss], and pin 4 [Vdd]
to make contact in the socket before the other pins.
Allowing Ground and power to be connected first
to the SD socket.
Pins CLK, CMC, DAT0, DAT1, DAT2, and Vss
make connection after pins 3 and 4 make contact.
Pin 1, DAT3 makes contact last.
Of course pins 3 and 4 are also the last
pins to lose contact with the socket.

The MicroSD form factors picture [left]
is used under GNU License

Comparison of SD Memory Card sizes
SD Card, miniSD Card, microSD Card

{Back to Secure Digital Card Index}

Acronyms; Smartmedia Host Controller (SMHC), Secured Digital Host Controller (SDHC)

Engineering Design Key words: SD, Secure Digital, SDIO, DataFlash card, MultiMedia Card, MMC Card, Form Factor, SPI, pinout, Pin out Personal Computer Memory Card International Association, PC Card, Interconnect, Electrical layer, Interface Standard Data Bus, Standard, Specification, Spec, Interface, Removable, IC, Physical Interface, Description, Manufacturer, Personal Computer, PC, Pin-out, Connector Pins


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