SDHC (Secure Digital High Capacity)

SDHC stands for Secure Digital High Capacity. It is a format for new memory cards that is based on the 2.00 specification of the SDA (Secure Digital Association).The name Secure Digital is due to their ability to protect copyright, using digital copyright management. This has made these memory cards a favorite choice in the audiovisual industry. These flash memory cards are available in various capacities, the minimum being 4 GB. SDHC cards are removable and are used in compatible digital devices like MP3 players, camcorders, camera phones, etc.

Why SDHC?

Today, everyone uses digital cameras, MP3 players, etc. The use of high definition and high resolution in videos and photography drives the escalating demand for high-capacity flash memory cards. They not only provide an ample amount of storage space, but also operate at a guaranteed minimum speed of data transfer. However, the maximum speed is typically much higher than this minimum speed.

Classification Of SDHC

The cards are classified into three classes on the basis of data transfer speed:

• Class 2: This class has a minimum speed of 2 MB/sec.
• Class 4: This class has a minimum speed of 4 MB/sec.
• Class 6: This class has a minimum speed of 6 MB/sec.

The SDA V 2.00 Specification

SDHC cards are based on the SDA V 2.00 specification, which includes the capacity of the card, the dimensions, the number of pins, the voltage, and the file system:

• The capacity of the card: 4-32 GB
• Dimensions are quite small, about the size of a postage stamp: 24x32x2.1 mm
• The number of pins is nine.
• The voltage is 2.7-3.6 V.
• The file system is FAT32.

Having these classifications in place in the industry will benefit consumers in the long run. According to these common new standards for all manufacturers, consumers can make an informed decision about the product that they want to purchase, depending on the price, their need, and, most importantly, the type of cards that their device supports.

Who Can Use SDHC Cards?

Devices that comply with the SDA V 2.00 specification can use these SDHC memory cards. Devices that support only versions 1.00 and 1.1 will not be able to use these cards. These cards are priced on the basis of their capacity and speed. The consumer will need to check that his or her device is compatible before using SDHC. It is also important to check what class of HC card the device supports because it's a waste of money to buy a card that has a higher transfer rate/speed than the device can support. However, there are a huge number of formats available in the market. The manufacturers have proprietary rights as well. So it is important to check the manual for the list of cards that the device can support.