Circuit is attached.
Determine the dc voltages, assuming K = 1 mA/V2 and VTH = 1V
Formulae for n-channel MOSFET
iDS = K[2(vGS-VTH)vDS - v^2DS] for triode region
iDS = K(vGS-VTH)^2 for saturation region
(I'm not sure why VTH is not given negative for this P-channel MOSFET - any suggestions?)
My solution (not sure!):
Let us consider P-channel MOSFET (as shown in picture) is operating in saturation.
IDS = K(vGS-VTH)^2 [ we have I = Is = Is = IDS = 2mA]
or, 2 = 1 (VGS - 1)^2
or, VGS = 1 plus/minus 2 square-root
or, VGS = 2.141V or -0.414V
As for P channel, VGS has to be less or more negative than that of VTH.
So, VGS = -0.414V
Applying KVL from Source to Get:
10 - VS - VSG = 0
or, VS = 10 + VGS = 9.59V
Now, VD = 6.8*2 - 10 = 3.6 V
VDS = VD - VS = 3.6 - 9.59 = - 5.99V
So, VGS = VG - VS
or, VG = -0.414 - 9.59 = 9.18V
Test, for saturation VDS ≤ VGS - VTH
-5.99 ≤ -0.414 - 1 true!
Please check my calculations and advise, Thanks.
cktMan
Determine the dc voltages, assuming K = 1 mA/V2 and VTH = 1V
Formulae for n-channel MOSFET
iDS = K[2(vGS-VTH)vDS - v^2DS] for triode region
iDS = K(vGS-VTH)^2 for saturation region
(I'm not sure why VTH is not given negative for this P-channel MOSFET - any suggestions?)
My solution (not sure!):
Let us consider P-channel MOSFET (as shown in picture) is operating in saturation.
IDS = K(vGS-VTH)^2 [ we have I = Is = Is = IDS = 2mA]
or, 2 = 1 (VGS - 1)^2
or, VGS = 1 plus/minus 2 square-root
or, VGS = 2.141V or -0.414V
As for P channel, VGS has to be less or more negative than that of VTH.
So, VGS = -0.414V
Applying KVL from Source to Get:
10 - VS - VSG = 0
or, VS = 10 + VGS = 9.59V
Now, VD = 6.8*2 - 10 = 3.6 V
VDS = VD - VS = 3.6 - 9.59 = - 5.99V
So, VGS = VG - VS
or, VG = -0.414 - 9.59 = 9.18V
Test, for saturation VDS ≤ VGS - VTH
-5.99 ≤ -0.414 - 1 true!
Please check my calculations and advise, Thanks.
cktMan