A Very Basic NMOS question

S

Saran

Guest
Hello All,

I am a computer science person. I am learning Analog VLSI. I have a
basic question about MOSFETS. For instance, consider two NMOS
transistors series connected. I have VDD = 5V, VG (dev1) = 3 =
VG(dev2). Device two source is connected to ground.

\(Vdd = 5V)
|
|------out1
N1(gate vol=3v)
|
|------out2
N2(gate vol = 3v)
|
|
gnd

If the nmos can be considered as a simple resistor with the
appropriate voltages ensuring the conduction through the device, why
is by out2 showing me zero (I am using cadence spectre for
simulation). Should I not expect out2 current to be the drain current
of N2?

I am really sorry if this question is too basic for you. I have been
scratching my head over this question for too much time now..I thought
you people might help me out.

Thanks,
Saran
 
The problem was with spectre. To see the current at the source, I
needed dummy voltage sources (0V) connected. Thanks.

Saran


saranyan13@gmail.com (Saran) wrote in message news:<6715d7c8.0410080636.14cb0a9f@posting.google.com>...
Hello All,

I am a computer science person. I am learning Analog VLSI. I have a
basic question about MOSFETS. For instance, consider two NMOS
transistors series connected. I have VDD = 5V, VG (dev1) = 3 =
VG(dev2). Device two source is connected to ground.

\(Vdd = 5V)
|
|------out1
N1(gate vol=3v)
|
|------out2
N2(gate vol = 3v)
|
|
gnd

If the nmos can be considered as a simple resistor with the
appropriate voltages ensuring the conduction through the device, why
is by out2 showing me zero (I am using cadence spectre for
simulation). Should I not expect out2 current to be the drain current
of N2?

I am really sorry if this question is too basic for you. I have been
scratching my head over this question for too much time now..I thought
you people might help me out.

Thanks,
Saran
Click to expand...
 
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