.bode: How could I know/find which is the best value for the AMP?


How could I know/find what is the best value for the AMP = Minimum amplitude of perturbing source?

Also, can this .bode plot be used for dc dc LLC converter for example?

You can perform a time domain (.tran) analysis with a perturbing source to study the impact of the perturbing signal level at different frequencies before setting up signal amplitude (including .option relates to amplitude) for the .bode analysis.
This is necessary because the .bode command doesn’t provide time domain simulation data, even though it internally runs a .tran analysis to collect data for the bode plot.
This is also the reason why some community members not use .bode as they prefer to observe the time domain signal too.

Do you have any example on this? How to choose the best value for perturbing amplitude between multiple amplitude, and what is the impact of perturbing signal level at different frequencies?