Pen drive

The presentation gives information about origin of pen-drive,description,features, mechanism, available brands.
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1. PEN DRIVE

2. 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 .

3. Description : A pen drive, or a USB flash drive, is a portable data-storage device . 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 ,

4. Components involved: 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

5. Additional components 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 memory. Unpopulated space – provides space to include a second memory chip. 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 .

6. Working mechanism: 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.

7. 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 memory chip. 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 .

8. The second chip which is shown in the image above is a NAND type flash memory which has fast read, write and erase cycles .

9. 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.

10. Available brands 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.

11. 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 world.  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