LTspice ideal OTA subcircuit problem

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5O5mm

Joined May 15, 2021
15
Hi, I tried to construct a subcircuit model of an ideal Operational Transconductance Amplifier (OTA). It's nothing more than a voltage-controlled current source but it doesn't work correctly in some circuits.

Here is the circuit equivalent and the netlist of the OTA:
1.png

And here is the circuit I try to simulate. Op-Amp works correctly as a comparator. The OTA and capacitor should've act as an integrator but no. (Resistor in the end is just for the output node not to be floating since output is current, Vout = Io*1)

4.png


The output should be a triangle wave right? Since (square wave) -> (integrator) -> (triangle wave)

5.png


When I use a behavioral voltage source as an equivalent of the OTA integrator it works fine. What is the problem with the subcircuit?

6.png

7.png
 
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