Simulating Rene Schmitz's MOSFET filter seems to have erratic behavior.

enter image description here

Simulated version

From what I understood, you have to make the sure that the gain level after the first opamp is within 600 mV. Changing the two 10k feedback resistors causes the simulator to stop.

Even with the 270k / 10k pair I don't reach >600 mV, an online calculator shows a gain factor of 0.037037037037037035 and amplitude of 0.18518518518518517. In the simulator, it swings erratically between 0 and 7.x V.

Would this circuit work with any N channel MOSFET or is it just inherent to the CD4007?

Datasheet cd4007ub, the IC has some weird connection between the MOSFETs.

Is this a problem of the simulator? The circuits doesn't show errors or bad connections.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.