Hello everyone,
I'm currently tring to determine the oscillation frequency of an oscillator theorethically but I'm having trouble starting (and olso the amplitude of the voltage output)
Here is the circuit i want to study:

Since Id is constant and transfer through the oscillation circuit via matched p transistor our circuit can become this:

But then i don't how to start for the calculation?

Hope someone can help me with this
Kind regard
Jérémie

 

brings back memories... many years ago i played with all kind of radio circuits. one of them was version of this oscillator, though i was using it for FM and with BJTs.

the L1 and L2 are actually not two separate inductors. they are one inductor with a center-tap.
to get the frequency you need to take into account L and C values but there are also parasitic capacitances that will depend on used components and of course on actual construction.

 

Hello again, thanks for your answer,
Actually I would like to keep two separate inductors, i don't know if it will work. I'v made a small signal model to try to obtain the frequency oscillation but i'm not sur about it:


It's a bit messy but i used the cmos equivalent model (without the parasitic to begin with).


Do you think it's correct?

Thanks for your answer.