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USB Flash Drives Explained

USB flash drives have become extremely popular as giveaways and incentives in recent years. They are used on a daily basis for storing and transporting data but like so many other computer-related items it is sometimes a mystery how they actually work!

There are typically three parts to a flash drive:

• Male type-A USB connector – provides an interface to the host computer.

• USB mass storage controller – implements the USB host controller. The controller contains a small microcontroller with a small amount of on-chip ROM and RAM.

• NAND flash memory chip – stores data. NAND flash is typically also used in digital cameras.

A typical flash memory device has a housing including a small printed circuit board (PCB), and an integral connector for connecting to a USB port on a computer. The USB flash drive is connected to a computer either by direct connection or via a USB hub. When plugged into a USB port, the computer’s operating system recognizes the flash memory device as a removable drive and allows data to be retrieved from and added to the flash memory drive. Most flash drives require no other external power source or battery power source as they become active when connected with a computer.

Computers access modern flash memory systems very much like hard disk drives, where the controller system has full control over where information is actually stored.

Nothing actually moves in a flash drive: the term drive persists because computers read and write flash-drive data using the same system commands as for a mechanical disk drive, with the storage appearing to the computer operating system and user interface as just another drive.

In a nutshell, this means because USB memory sticks need no batteries and have no moving parts, they are significantly more reliable and robust compared to older storage technologies such as floppy disks and CDR/DVD-ROM media.

The USB connector is usually protected by a removable cap or by retracting into the body of the drive, although it is not likely to be damaged if exposed. Most flash drives use a standard type USB connection allowing you to plug into a port on a personal computer, but drives for other interfaces also exist.

The flash memory chips themselves are usually made in China and Taiwan by manufacturers such as Samsung, Micron, Hynix and Intel or other OEM brands. The chips are then assembled into the memory sticks and often branded with a customer’s logo.

Recycled or B Grade flash is common in such a price driven market so it is always worth checking with your supplier exactly who the flash was manufactured by. At USB2U we only use the highest grade quality chips for all of our Flash drives. Be very cautious with some companies who offer Flash drives for discounted prices incorporating B Grade chips. These types of Flash drives will only last a dozen or so times before they break or become unstable.

USB Flash drives are now an incredibly popular way of storing and carrying data and their utility has driven their use in the Promotion and Incentives market where branded USB Memory Sticks have become one of the mainstays of the industry

About the Author

Phil is part of the team at USB2U who are specialist suppliers of Branded and Promotional USB Memory Sticks. We offer fast turnaround times, excellent advice and support and free design and mock-ups. If you are considering Branded USB Memory Sticks or want a Custom USB Memory stick then please contact us – we ‘d be delighted to hear from you.

USB host mode on the HTC Desire