I made an inverter in LTSPICE and it's not working

Thread Starter

pkms37

Joined Mar 18, 2021
6
The circuit below works well
1617699194451.png
I refer to the netlist above and wrote the subckt file.

but the one with the subckt below is not working...
1617699228193.png
 

Thread Starter

pkms37

Joined Mar 18, 2021
6
Oh thanks Bordodynov!

By the way, I don't know much about the circuit and the parameters that I have to put.
So could you please let me know which parameters I should consider?
I thought it would be okay with the default values.

And what is the difference between the circuits I uploaded? with symbol and without the symbol?
 

LvW

Joined Jun 13, 2013
1,229
Just a small hint: In all simulation programms all nodes require a DC path to ground (an open circuit can be simulated with a resistor of 1e12 ohms)
 

Bordodynov

Joined May 20, 2015
2,836
Transistors with default parameters are very weak. W=L=100µm. VTO=0. They are not suitable for your case. The difference between the subcircuit and the circuit on the transistors is in the error. In the subcircuit the drain and gate of the transistors are mixed up. Look at my subcircuit diagram. I made a rearrangement.
2021-04-06_14-14-43.png
 

Thread Starter

pkms37

Joined Mar 18, 2021
6
As I see the SUBCKT model you showed me, the parameter values are very specific.
Is there anywhere I can refer to for those kinds of parameters or does it comes from the understanding of the device and the circuit?
 
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