xtal spice models
If a initial current isn't added, the circuit can work, only the startup time is very long! not as u say the circuit won't startup![/quote]
If you simulate a RC oscillator and you did not add initial condition, you will never start it up. why?
Added after 7 minutes:
Adding initial condition is to emulate the noise source, e.g., set initial condition voltage/current, powerup supply etc.., because, we know, there is no noise model for transient analysis. so we need add some disturbing signal to osc to made it bigger and bigger with positavie feedback. What I just want to know , from the view of sloving the differtial equations, how it works.
Thanks