A USB flash drive is a portable storage device that allows users to store and transfer files between computers. It uses flash memory instead of a magnetic disk, making it smaller than a floppy disk or CD. Early flash drives had limited storage capacities and transfer speeds, but technology has improved allowing newer drives to store more data and transfer faster. Flash drives are durable, portable, and support a wide range of operating systems. However, their small size also means they can be easily misplaced, and damaged drives cannot be repaired like scratched CDs.

1. Universal Serial Bus (USB)

2. A pen drive is a portable Universal Serial Bus (USB)
flash memory device for storing and transferring
audio, video, and data files from a computer.
USB flash drives are typically removable and
rewritable, and physically much smaller than
an optical disc.

3. • BEFORE PENDRIVE……...
FLOPPY DISC / DISKETTE,
1.44 megabytes

4. • COMPACT DISC
LIMITED STORING CAPACITY
SIZE
Optical discs require special drives to read/write.

5. Pua Khein Seng
First PEN DRIVE appeared in market in 1995 & 1998
with maximum transfer rate of 12mbps
High speed PEN DRIVES released in market in 2000
with speed of 480 mbps

6. Components involved
Standard-A USB plug.
controller chip is the ‘brain’ of the flash drive
NAND flash memory chip(s)
Crystal oscillator It is used as a digital “clock”.

7. Crystal Oscillator: It is used as a digital “clock”.
6)LED indicator light
3) The controller chip is the ‘brain’ of the flash drive.
2 ) NAND Flash memory storage chip is the
place where all our files are stored.

8. Working mechanism:
• Pen Drives have a storage capacity up to 256 GB.
The internal circuitry of the pen drive draws
power from the computer for its operation
• There are two chips, one is the USB controller
and the other is the flash memory chip.
• The IC SK6211 is a controller which facilitates the
data communication between the PC/Laptop and
the flash memory (EEPROM) of the pen drive

9. • The second chip is a NAND type flash memory
which has fast read, write and erase cycles.
• The crystal oscillator used here runs at a clock
frequency at 12 MHz

10. LATEST PENDRIVES

11. USES AND FEATURES………
MAJOR CONTRIBUTION IN MEMORY STORAGE…
EASY TO CARRY, PORTABLE ,FEASIBLE & DURABLE
RESISTANCE TO SCRATCHES AND DUST
Can store more data and transfer faster than much
larger optical disc drives like CD-RW or DVD-RW drives
Pen drives are supported by operating systems such
as Linux, OS X, Windows, Unix-like systems and read by
many other systems such as the Xbox 360, PlayStation 3,

12. DISADVANTAGES
• SIZE : Being small leaves some devices to be
easily misplaced
• IT BREAKS IT GONE : Compared to some CDs
that can be repaired once scratched to
retrieve data , USBs once they fail they fail .

13. .