Definition of a pen drive
• A USB flash drive is a data storage device that
includes flash memory with an
integrated Universal Serial Bus (USB) interface.
USB flash drives are typically removable and
rewritable, and physically much smaller than
an optical disc.
• A pen drive, or a USB flash drive, is a portable data-storage
• Most weigh less than 30 grams
• Storage capacities as large as 2 TB are planned, with steady
improvements in size and price per capacity expected.
• USB flash drives are often used for the same purposes for
which floppy disks or CDs were used, i.e., for storage, back-
up and transfer of computer files.
• USB flash drives use the USB mass storage standard,
supported natively by modern operating systems such
as Linux, OS X, Windows, and other Unix-like systems, as
well as many BIOS boot ROMs. USB drives with USB 2.0
support can store more data and transfer faster than much
larger optical disc drives like CD-RW or DVD-RW drives and
can be read by many other systems such as
the Xbox 360, PlayStation 3,
• A flash drive consists of a small printed circuit board carrying the
circuit elements and a USB connector, insulated electrically and
protected inside a plastic, metal, or rubberized case which can be
carried in a pocket or on a key chain.
• There are typically four parts to a flash drive:
• Standard-A USB plug.
• USB mass storage controller
• NAND flash memory chip(s)
• Crystal oscillator
• Cover - typically made of plastic or metal - to protect the electronics
against mechanical stress and even possible short circuits
• The typical device may also include:
• Jumpers and test pins – for testing during the flash drive's
manufacturing or loading code into the microprocessor.
• LEDs – indicate data transfers or data reads and writes.
• Write-protect switches – Enable or disable writing of data into
• Unpopulated space – provides space to include a second memory
• USB connector cover or cap – reduces the risk of damage and
prevents the entry of dirt.
• Transport aid – the cap or the body often contains a hole suitable
for connection to a key chain or lanyard.
• Some drives offer expandable storage via an internal memory
card slot, much like a memory card reader.
• USB Flash Drives or commonly called as Pen
Drives are popular removable storage media
having a storage capacity up to 256 GB.
• The internal circuitry of the pen drive draws
power from the computer for its operation. They
have an integrated USB interface to communicate
with the computer. The important parts of the
pen drive are USB connector, crystal oscillator,
memory chips and a controller to interact with
the PC. The pen drive used here has storage
capacity of 4GB.
• The USB connector is protected by either
retracting into the body or by covering by a
removable lid. There are two chips, one is the
USB controller and the other is the flash
• The IC SK6211 shown in the above image is a
controller which facilitates the data
communication between the PC/Laptop and
the flash memory (EEPROM) of the pen drive.
• The second chip which is shown in the image
above is a NAND type flash memory which has
fast read, write and erase cycles.
• This image shows the other side of PCB. The
second memory chip, a crystal oscillator and a
number of surface mount components are
soldered which are required for the operation
of the pen drive.
• The crystal oscillator produces the clock signal
for the correct operation of the device. The
crystal oscillator used here runs at a clock
frequency at 12 MHz.
• Kingston: Kingston's DataTraveler
USB Flash Drive is the latest in portable flash
memory storage from the greatest name in
memory. Reliable and easy to use.
• Transcend:JetFlash are a series of flash
based USB drives designed and manufactured
by Transcend, a multi-
national Taiwanese company.
• Sandisk: Sandisk’s flask memory technologies are
used by many of the world's largest data centers,
embedded in the most advanced smartphones, tablets,
and laptops, and are trusted by consumers around the
• HP: HP offers a broad range of flash drive to enhance
storage capabilities for your business and home PCs.
• Iball: iball offers a wide range of portable devices
with it’s most recent and innovative new product,
called the hybrid dual connector pen drive. The dual
connector flash drive comes with standard USB 2.0 on
one side and a microUSB connector on the other..
• Other available brands are
samsung,lg,song etc etc