Applet Worksheet
[This worksheet may be suitable for Computer Lab Recitation or for Homework assignment for introductory-level microelectronics courses. If you like, here is a MS Word file of this worksheet for three MOSFET applets.]
II. MOSFET: Channel Continuous (Triode mode) or Channel
Pinched OFF (Saturation)
Applet: http://jas.eng.buffalo.edu/education/mos/mosfet/v11/mos_1.html
Applet Introduction: This applet shows the Channel
region versus the Gate-Source bias, Vgs, and the Gate-Drain bias, Vgd.
The I-V curves show the Id-Vds, the Drain current versus Drain-Source bias
at all biasing conditions; and the Id-Vgs, the Drain current versus Gate-Source
bias when the MOSFET is in Saturation. The red-dot indicates the
current Biasing condition.
3. N-channel
ix) Applet Preparation: Select N-channel, Vt=1.5 V ==> Use Up/Down arrows to change Vgs and Vgd. Set Vgd = 0V
x) Change Vgs and find at what Vgs the channel forms at the Source-end ?
Vgs = ( ) volts
xi) From the above, what is the relationship of Vgs vs. Vt for the N-channel to form at the Source-end ?
Vgs vs. Vt: ( )
xii) Now, change Vgd and find the Vgd value at which the Channel is continuous through the Drain-end (if the channel is not continuous, then the channel is pinched off at the Drain-end):
Vgd = ( ) Volts.
xiii) From the above, give a relationship for Vgd vs. Vt for the N-channel.
Continuous Channel (Triode) : Vgd vs. Vt ==> ( )
Channel is pinched off at Drain end (Saturation): Vgd vs. Vt ==> ( )
Note the location of red-dot on the Id-Vds curve. The red-dot is the current biasing condition Vgs and Vgd of the MOSFET.
4. P-Channel
xiv) Applet Preparation: Select P-channel, Vt= -1.5 V ==> Use Up/Down arrows to change Vgs and Vgd. Set Vgd = 0VNote the location of red-dot on the Id-Vds curve. The red-dot is the current biasing condition Vgs and Vgd of the MOSFET.
xv) Change Vgs and find at what Vgs the channel forms at the Source-end ?
Vgs = ( ) volts
xvi) From the above, what is the relationship of Vgs vs. Vt for the P-channel to form at the Source-end ?
Vgs vs. Vt: ( )
xvii) Now, change Vgd and find the Vgd value at which the Channel is continuous through the Drain-end (if the channel is not continuous, then the channel is pinched off at the Drain-end):
Vgd = ( ) Volts.
xviii) From the above, give a relationship for Vgd vs. Vt for the P-channel.
Continuous Channel (Triode) : Vgd vs. Vt ==> ( )
Channel is pinched off at Drain end (Saturation): Vgd vs. Vt ==> ( )
[You may continue and complete the questions below.]
| Vgs | Vgd | Operation Region |
| 1.7 V | 1.7 V | Triode |
| 2.5 V | 2.0 V | |
| 2.5 V | 0 V | |
| 1.3 V | 1.0 V |
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