Transcript FETs and Flash Memory [x]

Flash Memory
…and a tour through FETs
Junction Field Effect Transistor
Metal Oxide Semiconductor
Field Effect Transistor
Actual MOSFET Devices
Single MOSFET on Intel chip
Enhancement MOSFET
MOSFET Motor Control
Circuit component
Motor Control Circuit
Floating Gate MOSFET = Flash
+++++
Assume:
VDS =VD - VS =+12V
What happens if?:
VGS =VG – VS= +12 V
Then what
happens?:
to ‘jailed’ electrons if
VGS is set to 0V?
Reading Memory State
Change in Threshold Voltage due to Screening Effect of Floating Gate
Read mode: Apply intermediate voltage, check whether current is flowing or not
Writing Memory State
Control gate voltage determines whether electrons are
injected to, or push/pulled out of floating gate.
Block Structure
Writing block structure:
The ole 2-step
1
2
Step 1: Set all bits to 1 (clear out electrons from floating gate)
Step 2: Set selected bits to 0 (inject electrons from control to floating gate)
Voila – flash memory stick
Citations/Image Sources
• http://www.learnabout-electronics.org/fet_01.php (JFETs)
• http://volga.eng.yale.edu/index.php/Main/Semiconductors#M
OSFET
• http://www.electronics-tutorials.ws/transistor/tran_7.html
(MOSFET motor control)
• http://www.engadget.com/2011/10/31/engadget-primedssds-and-you/
• https://www.youtube.com/watch?v=msi5GDz9JIw
(hyperscience youtube channel – reading flash contents)