Hi,

   Recently I am confused about my phase noise simulation of an oscillator. Because the oscillator has the reference bias circuit, the settling time is a bit long if all of the circuits is enabled at the beginning. Hence inside the ring oscillator, I add a delay cell to postpone the enable signal of the ring oscillator and let the reference bias circuit to settle at the beginning.
   My question is: if I use periodic steady state simulation, is it possible to get the steady state in the simulation with the delayed enable signal for the oscillator.
   If I can do it, I think I should take care the initial transient setup in the simulation. In Cadence, it is called tstab. I first run the transient simulation and make sure the oscillator can oscillate stably, then I set the initial transient time in the periodic steady state simulation. Am I doing in a good way?
   From my view, the initial transient in the periodic steady state simulation will take care the delayed enable signal and the oscillator settling time. After the steady state is found, the phase noise simulation can start to run.
   Please give me some hints. The reason I add the delayed enable signal for the oscillator is just to separate the settling between reference bias circuit and the oscillator.
   Thank you very much.

Thank you very much, Ken. Currently I am not using SpectreRF unfortunately. I have solve the problem, and the simulation failure is due to the weakness of the software I am using. Thank you again for your clear explanation of PSS simulation.
Jacki