Question regarding NMOS and ouput

[Hellsin]

Can any pro out there please guide me to the answer for A and B ?

Thank you very much

 

[udayan92]

How much is the threshold voltage?(that is Vt)?
And are both the transistors in saturation/cut off/triode mode of operation?Please specify......

 

[Hellsin]

Let say the threshold voltage is 0.7V
both trans are in saturation mode
what will be it ?

 

[udayan92]

Ok...for saturation mode,equation is..
Vds=Vgs-Vt
0.7-Vs=0.7-Vs-0.7...and solving..
Vs will cancel out...looks like it cannot be solved...or maybe I am wrong.
Are you sure that the drain voltage and the gate voltage is 0.7V..??check again the figure..there could be some mistake(s).

 

[erikl]

View attachment 104984

Can any pro out there please guide me to the answer for A and B ?

In order to evaluate the voltages @ A & B, you need a resistor from B to GND.
The voltages @ A & B then depend on the threshold voltage Vt0 and the resistor value: View attachment 2_NMOS_in_series.pdf