Is there a more elegant and/or simpler method to model a repeating, damped sinusoid from SPICE or LTSpice rather than chaining the damped SINE sources in series? Below is a schematic and the waveform I am attempting to recreate ad infinitum.
I'm attempting to simulate switching noise from a DC/DC converter from within LTSpice. The area of interest is the PCB parasitics which cause a repeating, damped sinusoid superimposed on the switching frequency output ripple.
The only method I have found to model a repeating, damped sinusoid is to use a series chain of SINE sources, each offset in time by 1/2 the switching frequency, and include a damping factor for the decay. For a short chain length this is manageable; however for a longer transient sim, the thing would become unwieldy.
Any ideas how to make this repeatable forever?
Answer
[Sorry for the necromancy]
Even if it has been answered, there is a much simpler, better, and faster way to do it:
V2 acts as a control source who outputs pulses with very narrow Toff. V1 has the trigger keyword which allows an external source turn on V1 when V(ctl) >= 0.5 and off when V(ctl) < 0.5. The trigger voltage can also have a specified value, for example [...] trigger V(ctl)<1.3. This provides an exact sine with an exact 1-exp(-x) decaying shape, set in V1.
No comments:
Post a Comment