Internal Structure of Pendrive
During the 20th and 21st century there have been many useful and wonderful inventions. Most of the technological inventions that came out during this interval were seen small in size. Pendrive was one among them. Pendrive or commonly called as USB (Universal Serial Bus) flash drive is a popular data storage media having a storage capacity of 512GB. This is a kind of memory card that can be plugged into the computers USB port and they are considered to be the best because they are faster, smaller and have longer life span. It is known as Pendrive mainly because of its size. They come in a wide variety of shapes, but the most common is the rectangular and flat shape. This small external hard drive does not require any outside power source for its operation because they get the power from the computer they are plugged in.
Usually, a Pendrive consists of a flash memory integrated with a USB interface. The great advantage of such a device is that they are rewritable and removable. Today, Pendrive is supported by modern operating systems like Windows, Mac OS X, Linux etc. Pendrive or USB flash drive are supported with USB standards like USB1.0 (12Mbps), USB2.0 (480Mbps) and USB3.0 (4.8 Gbps). In DVD players and other handheld devices, SD card is most suited. Pendrive represents an inexpensive and simple way of transferring data from a PC and accessing the transferred data on another PC. Due to this they are considered to be better than the other conventional storage devices like floppy disks or CD ROMs.
Inside a Pendrive
Pendrive usually consists of a PCB (printed circuit board) with a USB connector, power circuitry and a number of integrated circuits (ICs).One of the IC in the PCB provides an interface between the memory and the USB connector. The next IC is a NAND flash memory where all the files are stored. Pendrive or the USB flash drive uses the PCB as the means of transferring the data and power from the USB. Controller chip is considered to be the brain of pendrive. Figure below shows the internal structure of the USB flash drive.
1. USB Connector: It acts as an interface between the NAND flash memory chip and the computer to which the pendrive is plugged. USB connector is usually protected by a removable cap. Most pendrive uses a standard type-A USB connection which allows connection with a port on a PC. The pendrive utilize the power from computer via USB connector.
2. USB mass storage controller (or the controller chip): This chip helps to retrieve the information from the pendrive and it also helps in recording/reading the information on the NAND flash memory. It is basically a microcontroller with on-chip RAM and ROM.
3. Test points: They are electric pins used to stimulate and exercise the pendrive during assembly process.
4. NAND flash memory chip: Helps in the storage of files and all datas. Also it allows the erasing the information so that we can delete files and put new files into the pendrive.
5. Crystal Oscillator: It is a piece of quartz crystal designed to vibrate at a very particular frequency.
6. LED: Used to indicate if the flash drive is working properly.
7. Write-protect switch: An optional component used to safeguard the information saved on the flash drive.
8. Space to put a second NAND flash memory chip: Additional slot to put another memory chip which can increase the storage capacity.
Pendrive is commonly used to store and transport files like pictures, videos, any private documents etc.
- Security for the storage of Data, Application and Other software Files
The issue of data security and information security is very essential since the pendrive are used in many outside environments. For providing security, today many encryption systems are used.
- Computer Forensics and Law Enforcement
USB flash drive is used to carry the Computer Online Forensic Evidence Extractor (COFEE) application. COFEE is a set of applications designed to search and extract digital evidence on computers confiscated from suspects.
Today most PC firmware helps in permitting booting from a USB drive which helps to provide the launch of an OS from a bootable pendrive.
- Operating system installation
Many operating systems can be installed from the pendrive. Some of the operating systems are Windows7, Windows 8, Linux, Mac OS etc.
Today pendrives are used as a backup. By using the pendrive backup data is updated to the drive.
Advantages of Pendrive
- Portable and Lightweight.
- The flash memory used is non-volatile. Non- volatile memory is a type which helps to get back the information or data stored even when there is no power.
- Plug and play device. Plug and play means that the PC can recognize a device and load the new drivers for the hardware and begins to work with the device connected.
- Easy to use.
- Data transfer is easy.
- Durable and Reliable since they do not have any moving parts.
Disadvantages of Pendrive
- Due to its small size, they may be lost or misplaced.
- Limited to less number of erase and write cycles.
- Virus can easily affect the pendrive and the files stored in it can be damaged.
USB is considered to be one of the standards used for communicating with the computer. But Pendrive or USB flash drive is a data storage device. It’s known to the customer world through different names like thump drive, jump drive, memory stick, key drive, USB etc. As of the year 2013, pendrive with storage capacity of 1TB is available. Eventhough they have many disadvantages, its advantages make them to be used at a rapid pace with the increasing advancement in technology.