Secure Digital High Capacity, or SDHC, is a format implemented on flash memory cards. It was developed by Toshiba, SanDisk and Matsushita for portable use in most carry-around electronic devices, like cellular phones, digital cameras, PDAs, video game consoles and GPS receivers. SDHC cards have capacities that range from 4GB to 32 GB, in contrast to standard SD cards’ 8 MB to 4 GB.

The SDHC format has been known to perform well with the newer gadgets. It looks just like normal SC cards and often confuses most users. SDHC, however, has compatibility issues with the older devices.

SDHC cards require SDHC firmware — a device not found in older electronic devices. Also, the new format is not backwards compatible with SD format host devices. To be sure, look for the SDHC logo on cards and electronic devices you plan to purchase.

New Standard Created by SDHC

SDHC cards are market leaders when it comes to digital photography because of the way it preserves image integrity and because it guarantees minimum performance floors. The image compression and the quality of the memory in SDHC cards are also praised by the video industry. In fact, SDHC cards created a new rating for minimum data transfer directed towards both high-capacity and standard cards.

This new Speed Class enables the host product to check the fragmented state of the card and to measure the writing speed in every part of that card. The same host can also conclude where it could write the data depending on the speed requirement.

MiniSHDC and MicroSHDC

  • Mini SDHC was developed right after the miniSD for more speed class options and storage power with smaller space occupied. This was mainly developed for smaller and newer cellular phones. It can be used with miniSD adapters to share digital content with devices accommodating SD cards.
  • The microSDHC cards are known as the smallest memory cards which are ideal for media-rich files like videos, music and high-resolution photography. It offers a minimum of 4GB memory at the area size of 165 mm2.

The three classes of miniSDHC and microSHDC cards (class 2, class 4 and class 6) can transfer data up to 2, 4 and 6 MB per second.