SDHC

SDHC stands for Secure Digital High Capacity, a family of Secure Digital memory cards designed to extend the capacity of the original SDSC standard. Introduced by the SD Association in 2006, SDHC cards provide storage from 4 GB up to 32 GB and use the same physical size and electrical interface as conventional SD cards. They use 512-byte blocks with block addressing and employ the CSD register version 2.0, which enables capacity calculation up to 32 GB and governs the command set used by hosts.

Form factor and compatibility: SDHC cards retain the standard SD card form factor and interface. They are backward compatible with devices that support SDHC; however, many older devices that only support SDSC may fail to read SDHC cards unless updated. Some readers require firmware updates to enable SDHC support. MicroSDHC refers to the smaller micro-form factor that also uses the same capacity range when used with adapters, and shares the same compatibility considerations as SDHC.

File system and usage: SDHC cards are typically formatted with FAT32 and are widely used in cameras, mobile devices, and portable electronics for moderate storage needs. With the rise of SDXC, which extends capacity beyond 32 GB, SDHC has become common in devices and applications that do not require higher capacities.