>Depending on your (apparently secret) requirements...
Or I simply don't know yet. Pretty much all the requirements (=the rest of the circuit) depend on what kind of signal I can generate. The frequency can be between 1-10kHz. Amplitude can be between 200mV and 5V. I don't know how much THD (or any other parameter) affects to the device. I need to finish the design, build the device and test. And then probably, re-design the circuit, build another device and test again. Maybe at this point I actually know all the key parameters, including if THD matters or not.
But I do know today that I am iterating options how to generate sine wave - as clarified in the initial message including an example circuit.
Quadrature oscillator might be "the fresh idea I was looking for". Just that none of the first examples I tried to simulate on LTspice didn't work. Like this one:
(Attachment Link)
Probably a simulation related issue - I need to analyze it further...
sw guy
Now why couldn't you have simply said that earlier? A lot of time would have been saved.
Your first task is system modelling, to calculate what should work.
Your second task is system design and simulation, to determine allowable tolerances.
Your third task is detailed design, simulation, to verify you can implement the system.
Your fourth task is to build and test.
You are asking us about task 3, without having done tasks 1 and 2. That is bound to fail, slowly and messily.
You are doing the equivalent of jumping straight into coding, without having requirements nor architecture. See the problem?
Once you have a successful
system simulation, e.g. using a spice sine wave voltage source, you can build a lab prototype using an off the shelf function generator. Only after the lab prototype is.working does it become worth considering implementing your own generator.