I have a rather peculiar question. I am attempting to recreate the circuit below (from one of my labs) of a Common-Source Amplifier design with a bypassed Source Resistance in PSpice. It has the following parameters:
R1 = R2 = 100k
Rd = 1k
Vsig = 100mV peak sinusoidal
f = 5kHz
So far so good. I have the circuit set up the same way as the figure. For my simulation profile, I just want to see the input and output waveforms for now. My question is:
What do I connect to the Coupling Capacitor at the Drain, where the figure shows Vout?
I tried connecting it to Ground and placing a Voltage Pin at the Capacitor which just gave me a 15V DC waveform. I am also told that I should not connect a Load Resistance across it. I'm pretty much stumped on what to connect there and where exactly I am measuring Vout across…
In all of my homeworks and textbook excercises, Vout has been taken across a load resistance connected between Drain and Ground (for a CS Amplifier with bypassed Rs).
Below is my PSpice Circuit and input/output waveforms after connecting a Load Resistance as suggested. For some reason I am seeing signal attenuation instead of amplification..
Best Answer
In Spice simulation you sometimes find that the simulation won't run unless there is something like a resistor in place so a node is not floating. You can insert a 10G resistor for a load and it will behave much like it was floating. Or do as Jim Thompson recommended on sci.electronic.design back on Sep 22, 2004:
Or use a simulated scope probe like 10M in parallel with 10pF.