Question

For an N-channel enhancement-type MOSFET, if the source is connected at a higher potential than that of the bulk (i.e., VSB>0), the threshold voltage \( V_{th} \) of the MOSFET will

• A. Remains unchanged
• B. Decreases
• C. Change in polarity
• D. Increases

Hint:

When \( V_{SB}>0 \) in a MOSFET, the threshold voltage increases due to the body effect, which increases the voltage required to turn the device on.

Answer 1

The Correct Option is D

In an N-channel MOSFET, when the source is at a higher potential than the bulk (i.e., \( V_{SB}>0 \)), the threshold voltage \( V_{th} \) increases. This is because the positive voltage at the source creates a reverse bias at the source-bulk junction, which effectively increases the potential barrier, raising the threshold voltage. Thus, the correct answer is option (4).