Hi,
I am developing an analog and digital circuit optimizer and I use LTSpice as a simulator. This tool gives you the value of Length and Width of the transistors that optimizes certain metrics, such as Gain, Power consumption, Transconductance, etc. So far the program has worked very well, but I am facing a problem with the simulation of a OTA, wich has a differential voltage input.

The problem is that I do not know how to simulate a differential voltage input in Spice code. I am using this line, but I am not getting the expected values.

.dc v+ 0 5 1m v- 0 -5 1m

What I am trying to do is to change V+ from 0V to 5V and V- from 0V to -5V with a 1mV step; with the purpose of simulate a differential input, but it does not works.

I hope you can help me.

Regards

 

hi LA,
I use this method, I usually have the voltage limits as +/-10mV into a bridge circuit.
E
EDIT:
Alternate method. image 002

 

hi LA,
I use this method, I usually have the voltage limits as +/-10v into a bridge circuit.
E

Thanks for you answer. I'm going to try this method!

Regards

 

hi LA,
Relook at post #2 for DC option.
Eric