Hi,
studying opamps I came across an apparently SimulIDE strange behaviour. I was working with an inverter configuration and noticed that if I incremented the feedback resistor (Rf) the gain woulldn't increase as expected (A = - Rf / Ri = -400).
With small Rf values, the gain was ok, but the higher the Rf the less exact the gain. In the image I'm sending, the gain should be around -400V, but it isn't.
![Opamp strange behaviour? Simuli13](https://i.servimg.com/u/f35/20/49/29/87/simuli13.png)
Then I discovered in properties a box labelled Gain with 1000 by default. I had to increase it to 1000000 to get the right value. Does anybody know why?
![Opamp strange behaviour? Simuli14](https://i.servimg.com/u/f35/20/49/29/87/simuli14.png)
studying opamps I came across an apparently SimulIDE strange behaviour. I was working with an inverter configuration and noticed that if I incremented the feedback resistor (Rf) the gain woulldn't increase as expected (A = - Rf / Ri = -400).
With small Rf values, the gain was ok, but the higher the Rf the less exact the gain. In the image I'm sending, the gain should be around -400V, but it isn't.
![Opamp strange behaviour? Simuli13](https://i.servimg.com/u/f35/20/49/29/87/simuli13.png)
Then I discovered in properties a box labelled Gain with 1000 by default. I had to increase it to 1000000 to get the right value. Does anybody know why?
![Opamp strange behaviour? Simuli14](https://i.servimg.com/u/f35/20/49/29/87/simuli14.png)
Last edited by blitobyte on Wed Apr 12, 2023 7:35 pm; edited 1 time in total (Reason for editing : Include a zip with sources so that other chatters can reproduce the problem.)