USB flash drives provide users with an enormous level of satisfaction and accessibility due to their massive storage capacities, low cost, and small size. USB flash drives serve an important role in our society and have a precedence over other means of data transportation. Where as computers used to have floppy disk drives as well as USB ports, the majority of modern computers now only have USB ports, eliminating the use of floppy disks entirely. In order to better explain how USB flash drives work, this article will explore the individual components that make up USB flash drives and the advantages and disadvantages of such technology.
Flash Memory
Flash memory refers to a type of computer technology that stores data, does not need constant electricity, and can be electrically erased and reprogrammed. Flash memory is used in many different appliances including memory cards, PDAs, laptop computers, MP3 players, digital cameras, mobile phones, game consoles, and most importantly, USB flash drives. Flash memory is fast and easy to access and is also resistant to falls. Flash memory is the most important component in a USB flash drive.
USB Interface
The USB interface within a USB flash drive is what allows the device to be plugged into a computer. The USB interface connects into a USB port that is built into the “tower” of the computer in question and can easily be removed without damaging the device. As a sign of the growing popularity of USB flash drives, both desktop and laptop computers have numerous USB ports built into the hardware. The actual metal conductor that makes up the USB interface is usually attached to a sliding bar that makes the USB flash drive fit in your pocket better but not all models have this feature.
MOSFET
MOSFET, or Metal-Oxide-Semiconductor Field-Effect Transistor, is a small device that is capable of both amplifying and switching an electronic signal. A MOSFET involves a metal “gate” that can generate a conducting channel between the two other contacts when a current is applied to it. MOSFETs are capable of handling 2000 watts of electricity and are used in almost all analog and digital circuits. MOSFETs are important in USB flash drives, however, because they use a very similar type of technology called a floating-gate transistor.
Floating-gate Transistor
A floating-gate transistor is very similar to MOSFET technology but instead of one gate, it has two. The top gate is called the control gate while the bottom is called the floating gate. The floating gate is completely insulated with an oxide layer. Each memory cell of a USB flash drive is a floating-gate transistor. When an electron is attached to the floating gate, it is trapped within the oxide layer and causes a difference in the voltage of the control gate. When this is measured as a whole, each memory cell makes up a 1 or 0 in binary code, depending on whether it is storing an electron or not.
Erasing Data
Erasing data from a USB flash drive actually involves the use of quantum mechanics. A process known as “quantum tunneling” is used in which a strong opposite charge is applied to the control gate in a floating-gate transistor which causes the electron to actually tunnel through the oxide insulation, returning the memory cell to a “1″ in binary code, meaning that it is empty. USB flash drives use to require that the entire device was erased at once but technology now allows us to simply delete what we no longer need or want and keep the rest.
Advantages
The main advantage of USB flash drives is that they are extremely small and can fit in a pocket. Another important feature is that USB flash drives do not contain any moving parts, unlike hard drives, which make them very durable and long-lasting. As technology has improved over recent years, USB flash drives have steadily increased their storage capacities while decreasing their price. USB flash drives also do not require any software to be installed in order for them to work with a computer as all computers that have a USB port have already been programmed to recognize a USB flash drive.
Disadvantages
USB flash drives are far superior to other means of data transportation but they do have a few drawbacks. For one, USB flash drives are so small that they are often lost or forgotten. Also, USB flash drives often do not have any write-protection software to keep viruses from infecting the USB flash drive. Even these minor problems, however, have been met and challenged in many recent models of USB flash drives.
