# LTSpice Transconductance Amplifier Simulation

I'm trying to simulate a band-pass transconductance amplifier in LTSpice, which looks like this:

I used the recommendations of this post - https://electronics.stackexchange.com/a/278870/87695 - and used a G component with a table to represent the voltage controlled current source in my LTSpice schematic.

I have done some estimations on the locations of the poles and zeros:

However, my simulation is not displaying the result I expect to see at all:

I suspect that I set up the voltage controlled current source incorrectly. Here are the parameters:

Any idea of what I did wrong? Thanks in advance.

• I am neither sure how the table there works, nor what you wanted to really see, but I personally usually use BI as the current source and then use V(nxxx) as the value in similar cases. maybe try that? – PlasmaHH Oct 4 '17 at 8:29
• That worked and I got the result that I expected: i.imgur.com/ZMi3jZy.png Thanks! – w00t Oct 4 '17 at 8:35
• Try a transient analysis with both variants, probably your table thing is causing clipping, I would try -10V -1A, 10V 1A – PlasmaHH Oct 4 '17 at 8:49
• Using a table with parameters -10V -1A, 10V 1A gave me the expected results! Good point. – w00t Oct 4 '17 at 8:56
• I see nowhere the need of a table(), so you can just replace the whole line with 0.1. BTW, behavioural sources, while versatile, can prove sluggish the higher the numbers, and their dynamic range, both on y and x axis, are reduced. Using a G source is the most accurate and fastest way to do it. Behavioural sources are good when there are more complicated expressions. – a concerned citizen Oct 5 '17 at 8:05

It might make more sense to use a BI source and simply set the current to a formula depending on the voltage of your node, this will not cause any clipping. I recommend though to label the net, as the n### automated node names can change.