# Pspice CMOS Inverter

Discussion in 'The Projects Forum' started by Runs212, Sep 12, 2015.

1. ### Runs212 Thread Starter Member

Mar 12, 2015
55
1
I'm trying to design a cmos inverter on pspice (just started using it this week) but I'm not quite getting the correct waveform. Below pictures shows my schematic and output graph. What am i doing wrong here?

2. ### #12 Expert

Nov 30, 2010
16,705
7,358
What is wrong about the wave form? The fact that it's going to negative 5 volts and there is no such supply voltage?

3. ### Runs212 Thread Starter Member

Mar 12, 2015
55
1
Yes, I expect it to switch from 0 to 5v.

4. ### Alec_t AAC Fanatic!

Sep 17, 2013
5,980
1,138
Put your V- probe be on the ground rail.

5. ### WBahn Moderator

Mar 31, 2012
18,093
4,920
When the voltage on the input node is 0V and the voltage on the output node is 5V, what is (Vout - Vin) equal to?

When the voltage on the input node is +5V and the voltage on the output node is 0V, what is (Vout - Vin) equal to?

6. ### eetech00 Active Member

Jun 8, 2013
685
118
I agree with Alex_t....

7. ### WBahn Moderator

Mar 31, 2012
18,093
4,920
Alex_t's suggestion certainly solves the problem. I'm just trying to get the TS to understand WHY they are seeing what they are seeing.

Sep 14, 2015
16
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use pulse of
v1=0
v2=5v
td=0
tr=0
tf=0
pw=0.5m
per=2m

9. ### WBahn Moderator

Mar 31, 2012
18,093
4,920
How will that help?

Having 0 rise and fall times can cause problems for the simulator. But even if it doesn't, how does this help answer the TS's question?

10. ### md yasir New Member

Sep 14, 2015
16
0
i just tried @WBahn in pspice 9.2 student version

11. ### WBahn Moderator

Mar 31, 2012
18,093
4,920
So? Again, how does that help the TS solve their problem. Their simulation was running fine. They were just having trouble understanding the values it was producing.

12. ### Runs212 Thread Starter Member

Mar 12, 2015
55
1
It was resolved. I probe should have placed at gnd. You notice i placed V- at the 5V source. Thanks everyone for your contributions and clarifications.