What is a USB Flash Drive?

What is a Flash Drive?

Equipped with a NAND-type flash memory and integrated with a USB 1.1 or 2.0 interface, a flash drive is a removable, compact and non-volatile data storage device that acts like a portable hard disk. However unlike the size of the latter, a flash drive is usually no longer than a cigarette lighter and only weighs half an ounce.

MECHANICS

Encased in a robust plastic casing, the flash drive contains a small printed circuit that connects to an embedded flash memory and a USB connector. This USB connector often protruded out of its casing to allow the user to plug the drive into the computer’s USB port. For safety purposes, a plastic cap is usually designed to cover and protect the USB connector.

COMPONENTS

1	USB connector
2	USB mass storage controller device
3	Test points
4	Flash memory chip
5	Crystal oscillator
6	LED
7	Write-protect switch (Optional)
8	Space for second flash memory chip

HOW DOES IT WORK?

When a flash drive is plugged into a computer’s USB port, the system’s plug and play capability detects the new hardware and displays a new logical drive in the My Computer workspace. Users can then access the drive by double clicking on the drive icon and simply drag any files across for transmission instantly.

USING THE DRIVE

The flash drive does not require an external power supply. Essentially, it runs off the small power supplied by the USB connection and is compatible with any computer that supports the Universal Serial Bus capability. New USB Flash Drives now support transfer rates up to 480 Mbits/s and storage capacity up to several GB (I recently purchased 32 GB thumb drive). Due to heavy marketing and product branding, flash drives have been coined and associated with names such as USB drive, key drive, thumb drive, keychain drive etc.

Additional Reading:

http://www.adrc.com/ckr/flash_drive.html
http://www.mediastoragedevices.com/flash-drives.html
http://en.wikipedia.org/wiki/USB_flash_drive