Cadence PSS simulation problem..

[liao0009]

pss simulation

Currently I was running pss and trans simulation for a class D amplifier, trying to find out the THD at the output. But the pss stops at 20.9% of the 2nd cycle every time. (the 1st cycle is completed). However, everything is fine if I run tran analysis alone.
Anybody know what problem it is? Thx!

 

[Alex_IC]

cadence pss

You can read about tuning for pss here
www.ece.osu.edu/~bibyk/ee894z/SpectreRF_0728.pdf
Try reduce accuracy of pss, set errpreset to moderate.

 

[liao0009]

pss cadence

Thx Alex_IC, after reading the notes above, I was still wondering..why pss can not continue but tran analysis can while no error is prompted?
Is there any way else we can get the THD without running the PSS analysis? I have already tried the function "thd" in calculator, but the result seems not to be convincible.
Anybody have some experience on Total Harmonic Distortion caculation with Cadence?

 

[Alex_IC]

pss simulations

I think this occur, because transient and PSS have diffrent accuracy setting. To calculate thd, you should take integer numbers of output signal periods (at least 10) from your simulation or you have to use windowing. Also use minimum time step at least 0.01*T