Memory Cards and its types

Memory Cards have become a popular storage medium for electronic devices. The main reason is that the memory is nonvolatile that holds the data even when there is no power given to the medium. The next thing is the size of the medium which is comparatively smaller. Its reusable feature adds to its rise in usage. Unlike some other storage mediums, it can be erased and reformatted multiple times. These memory cards are available at varying physical sizes and storage sizes depending upon the electronic device. 

Types of memory cards:

The types of memory card differs based on the size and the technical arrangements inside it or difference in manufacturing techniques. 

PCMCIA (Personal Computer Memory Card International Association)

These memory cards are always rectangular shaped with varying width, it can be split into 3 types as:

Type 1 -  3.3 mm thick, used as an additional component as ROM or RAM to a computer.

Type 2 -  5.5 mm thick, used for modem and fax modem cards.

Type 3 - 10.5 mm thick, used for portable devices

CompactFlash (CF)

      Scandisk invention, support 3.3V and 5V operation and can even switch between the two. CompactFlash is the most common types of digital camera memory. It is compatible with higher end digital cameras. There are two types of CompactFlash, Type I and Type II. Type II is thicker than Type I. Type II CompactFlash is usually a higher capacity card like 512MB or 1GB card.

Type 1 -  42.8mm x 36.4mm x 3.3 mm thick

Type 2 -  42.8mm x 36.4mm x 3.5 mm thick

Advantage:

■ CompactFlash have a controller chip that allows for higher transfer rates.

■ Inexpensive and easy to find.

■ Work in a large variety of digital cameras.

Disadvantage:

■ CompactFlash is a bit bigger than most other types.

Used in:

■ Higher end digital cameras and digital SLRs.

Secure Digital Card (SD card)

      In use since 1999, SD Memory Cards are now available in capacities between 16 Megabytes and 1 Gigabyte, and still growing. Secure Digital card is basically the second generation Multimedia Card. They are exactly same as MMC physically, other than the extra locking switch on the SD Card. The locking switch prevents data from being read, written, and deleted from the storage card.

Type 1 - MiniSD Card : This was developed to meet the demands of the mobile phone market. The MiniSD Card is nothing but a smaller version of the original SD Card.

Type 2 - MicroSD Card : The microSD Card is even smaller than the miniSD Card. The microSD Card is designed for use in cellular phones and small mobile devices. The microSD Card can accessed in a SD Card slot via an adapter.

Advantage:

■ Best for Mobile Phones

■ Locking system to prevent the data from being read and deletion

Disadvantage:

■ For Mini and Micro Card, Adapter is required to connect it in SD Card Slot

Used in:

■ Any small portable devices such as digital video camcorders, digital cameras, handheld computers, audio players and mobile phones.

SmartMedia Card

      SmartMedia used to be one of the most common types of digital camera storage media. It was jointly invented by Olympus and Fuji.

Advantage:

■ It is smaller and thinner that CF cards.

■ It also has contact pins directly on the surface of the card.

Disadvantage:

■ SmartMedia is limited to only 128MB .

Used in:

Olympus and Fuji digital cameras.

MultiMediaCard (MMC)

      The MultiMediaCard (MMC) standard was introduced by SanDisk and Siemens in 1997. The card itself is 32 mm x 24 mm x 1.4mm and is often used in place of the SD card.

Advantage:

■ Transfer speeds of a MMC is around 2.5MB/s 

Used in:

SD Card readers.

Memory Stick

      Sony developed the Memory Stick technology for their CyberShot digital cameras and other Sony electronic devices. Memory Stick uses a serial interface to transfer data between the host device and card. But the Sony Memory Stick has a 128 MB limitation.

Type 1 - PRO : Sony Memory Stick PRO is the new Standard to eliminate the 128 MB limitation. Currently, Memory Stick PRO is available up to 1 GB. The Memory Stick PRO format has a transfer rates up to 480Mb/s. It is commonly used in high megapixel digital cameras and digital camcorders.

Type 2 - DUO : Memory Stick Duo and Memory Stick Pro Duo are basically smaller version of the Memory Stick Pro. The Duo has pin-to-pin compatibility with its older and larger Memory Stick sibling.

Type 3 - MagicGate : MagicGate is Sony’s name for digital rights management (DRM), a copy-protection technology. It encrypts the data stored on the card and enforces control over how the files on the card are copied.

Advantages:

■ Transfer rates are very fast

■ Best for High megapixel camera

Disadvantages:

■ Compatible with Sony products only

Used in:

■ Sony Digital Cameras and Camcorders

xD-Picture Card

Abbreviated as xD (Extreme Digital), the xD-Picture Card is a type of removable flash memory designed for use in digital cameras. 

Advantage:

■ The xD is ultra-compact with its size of 20mm x 25mm x 1.7mm.

Used in:

Many models of digital cameras made by Olympus and Fujifilm.

Tips of Memory Card users:

■ Sturdy: Memory cards are quite sturdy and you can expect cards to be capable of working through more than one million data write/read/erase cycles. You can expect a memory card to be capable of withstanding around ~10,000 insertions. 

■ Weakest point: The card itself has its weakest point at its socket connectors, which are used when you remove and reinsert the memory card into a device.Damage to the card or the data contained on it can happen if you try to eject the card from the device or card reader, or if you try and turn the device off while you are transferring the data to or from the memory card. So definitely avoid doing that to protect your data and card itself.

■ Care Needed: Like with any consumer electronic or device, proper care is required by the users to meet the lifespan of the device. You should avoid applying too much pressure on your memory cards, and never drop or bend the card either. When the correct memory card is being used in a device, it will fit into the slot only in one direction and it will easily slide and click into place. You should never have to apply any amount of pressure to make the card fit. Memory cards should also be kept away from electrostatic sources and should never be introduced to direct sunlight or extreme ranges of temperatures.

Memory Cards: Key Terms

NAND 

NAND Flash architecture is one of two flash technologies (the other being NOR) used in memory cards such as the CompactFlash cards. It is also used in USB Flash drives, MP3 players, and provides the image storage for digital cameras.

USB card reader 

A small USB plug-and-play device used to read, copy and back up data from portable flash memory cards such as an SD Card, MiniSD, MicroSD, SIM and others that are used in a wide variety of consumer electronics products.

Smart card 

A small electronic device about the size of a credit card that contains electronic memory, and possibly an embedded integrated circuit (IC). Smart cards containing an IC are sometimes called Integrated Circuit Cards (ICCs).