Engineers Garage

  • Electronic Projects & Tutorials
    • Electronic Projects
      • Arduino Projects
      • AVR
      • Raspberry pi
      • ESP8266
      • BeagleBone
      • 8051 Microcontroller
      • ARM
      • PIC Microcontroller
      • STM32
    • Tutorials
      • Audio Electronics
      • Battery Management
      • Brainwave
      • Electric Vehicles
      • EMI/EMC/RFI
      • Hardware Filters
      • IoT tutorials
      • Power Tutorials
      • Python
      • Sensors
      • USB
      • VHDL
    • Circuit Design
    • Project Videos
    • Components
  • Articles
    • Tech Articles
    • Insight
    • Invention Stories
    • How to
    • What Is
  • News
    • Electronic Product News
    • Business News
    • Company/Start-up News
    • DIY Reviews
    • Guest Post
  • Forums
    • EDABoard.com
    • Electro-Tech-Online
    • EG Forum Archive
  • DigiKey Store
    • Cables, Wires
    • Connectors, Interconnect
    • Discrete
    • Electromechanical
    • Embedded Computers
    • Enclosures, Hardware, Office
    • Integrated Circuits (ICs)
    • Isolators
    • LED/Optoelectronics
    • Passive
    • Power, Circuit Protection
    • Programmers
    • RF, Wireless
    • Semiconductors
    • Sensors, Transducers
    • Test Products
    • Tools
  • Learn
    • eBooks/Tech Tips
    • Design Guides
    • Learning Center
    • Tech Toolboxes
    • Webinars & Digital Events
  • Resources
    • Digital Issues
    • EE Training Days
    • LEAP Awards
    • Podcasts
    • Webinars / Digital Events
    • White Papers
    • Engineering Diversity & Inclusion
    • DesignFast
  • Guest Post Guidelines
  • Advertise
  • Subscribe

Insight – How Pendrive works

By Ashutosh Bhatt November 15, 2011

 

USB Flash Drives or commonly called as Pen Drives are popular removable storage media having a storage capacity up to 256 GB. They are preferred over the other conventional storage devices like floppy disks or CD ROMs as they are faster, smaller and have a longer life span.

Image of a 4-GB Pen Drive

Fig. 1: Image of a 4-GB Pen Drive

 
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.

Internal Structure

Internal Structure of USB Showing PCB and Circuit Elements
 
Fig. 2: Internal Structure of USB Showing PCB and Circuit Elements
 
A printed circuit board carrying the circuit elements and a USB connector is shown in the above image. The circuitry is protected inside a pair of plastic cases (connected to each other by means of mechanical hooks) which can be carried in a pocket or a key chain. 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, which are discussed in detail later in the article.

Controller

IC SK6211 Controller
 
Fig. 3: IC SK6211 Controller
 
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. It is fully compatible with USB 2.0 protocols and USB Mass storage class V1.0 specification. The devices like memory card, hard disk, pen drive etc with high data storage capacity fall under the category of Mass Storage Devices. In order to communicate data with devices falling under this category the USB has defined a set of protocols. The operating system provides inbuilt libraries to handle such devices thereby preventing the need of any external drivers to be installed before using these devices. This controller IC can interface with all kind of NAND EEPROM.

Memory Chip-1

NAND-type Flash Memory Chip
 
Fig. 4: NAND-type Flash Memory Chip
 
The second chip which is shown in the image above is a NAND type flash memory which has fast read, write and erase cycles. The data is stored in memory cells of the EEPROM, known as “floating gate transistors” – a regular metal-oxide field effect transistor (M0SFET) consisting three terminals – source, gate and drain. The storage capacity of this memory is 2GB. There is another similar chip with storage capacity of 2GB on the other side of the PCB, thereby making the total capacity of the pen drive to be 4GB.  

Memory Chip-2 & Oscillator

Memory Chip of PCB and Various Components

Fig. 5: Memory Chip of PCB and Various Components

 

The above 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.
Closer View of Circuit Board
 
Fig. 6: Closer View of Circuit Board
 
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. 

Filed Under: Insight
Tagged With: data storage, memory chip, pendrive, usb
 

Next Article

← Previous Article
Next Article →

Questions related to this article?
👉Ask and discuss on Electro-Tech-Online.com and EDAboard.com forums.



Tell Us What You Think!! Cancel reply

You must be logged in to post a comment.

EE TECH TOOLBOX

“ee
Tech Toolbox: Internet of Things
Explore practical strategies for minimizing attack surfaces, managing memory efficiently, and securing firmware. Download now to ensure your IoT implementations remain secure, efficient, and future-ready.

EE Learning Center

EE Learning Center
“engineers
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, tools and strategies for EE professionals.

HAVE A QUESTION?

Have a technical question about an article or other engineering questions? Check out our engineering forums EDABoard.com and Electro-Tech-Online.com where you can get those questions asked and answered by your peers!


RSS EDABOARD.com Discussions

  • How to preserve hierarchical instance names like \adder_1/U1 in flattened gate-level netlist in Design Compiler?
  • Can anyone provide a guide or tutorial for Candece simulation?
  • Voltage mode pushpull is a nonsense SMPS?
  • High Side current sensing
  • MOSFET thermal noise in Weak vs Strong inversion

RSS Electro-Tech-Online.com Discussions

  • Photo interrupter Connections
  • Is AI making embedded software developers more productive?
  • Can I make two inputs from one??
  • Why can't I breadboard this oscillator?
  • Cataract Lens Options?

Featured – RPi Python Programming (27 Part)

  • RPi Python Programming 21: The SIM900A AT commands
  • RPi Python Programming 22: Calls & SMS using a SIM900A GSM-GPRS modem
  • RPi Python Programming 23: Interfacing a NEO-6MV2 GPS module with Raspberry Pi
  • RPi Python Programming 24: I2C explained
  • RPi Python Programming 25 – Synchronous serial communication in Raspberry Pi using I2C protocol
  • RPi Python Programming 26 – Interfacing ADXL345 accelerometer sensor with Raspberry Pi

Recent Articles

  • GigaDevice launches GD32C231 MCU series with 48MHz Cortex-M23 core and 64KB Flash
  • Advanced Energy releases 425 W CF-rated medical power supply in 3.5 x 6 x 1.5-inch format”
  • LEM combines shunt and Hall effect sensing in 2000 A current measurement unit
  • What is AWS IoT Core and when should you use it?
  • AC-DC power supply extends voltage range to 800 V DC

EE ENGINEERING TRAINING DAYS

engineering

Submit a Guest Post

submit a guest post
Engineers Garage
  • Analog IC TIps
  • Connector Tips
  • Battery Power Tips
  • DesignFast
  • EDABoard Forums
  • EE World Online
  • Electro-Tech-Online Forums
  • EV Engineering
  • Microcontroller Tips
  • Power Electronic Tips
  • Sensor Tips
  • Test and Measurement Tips
  • 5G Technology World
  • Subscribe to our newsletter
  • About Us
  • Contact Us
  • Advertise

Copyright © 2025 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy

Search Engineers Garage

  • Electronic Projects & Tutorials
    • Electronic Projects
      • Arduino Projects
      • AVR
      • Raspberry pi
      • ESP8266
      • BeagleBone
      • 8051 Microcontroller
      • ARM
      • PIC Microcontroller
      • STM32
    • Tutorials
      • Audio Electronics
      • Battery Management
      • Brainwave
      • Electric Vehicles
      • EMI/EMC/RFI
      • Hardware Filters
      • IoT tutorials
      • Power Tutorials
      • Python
      • Sensors
      • USB
      • VHDL
    • Circuit Design
    • Project Videos
    • Components
  • Articles
    • Tech Articles
    • Insight
    • Invention Stories
    • How to
    • What Is
  • News
    • Electronic Product News
    • Business News
    • Company/Start-up News
    • DIY Reviews
    • Guest Post
  • Forums
    • EDABoard.com
    • Electro-Tech-Online
    • EG Forum Archive
  • DigiKey Store
    • Cables, Wires
    • Connectors, Interconnect
    • Discrete
    • Electromechanical
    • Embedded Computers
    • Enclosures, Hardware, Office
    • Integrated Circuits (ICs)
    • Isolators
    • LED/Optoelectronics
    • Passive
    • Power, Circuit Protection
    • Programmers
    • RF, Wireless
    • Semiconductors
    • Sensors, Transducers
    • Test Products
    • Tools
  • Learn
    • eBooks/Tech Tips
    • Design Guides
    • Learning Center
    • Tech Toolboxes
    • Webinars & Digital Events
  • Resources
    • Digital Issues
    • EE Training Days
    • LEAP Awards
    • Podcasts
    • Webinars / Digital Events
    • White Papers
    • Engineering Diversity & Inclusion
    • DesignFast
  • Guest Post Guidelines
  • Advertise
  • Subscribe