Many different types of ideal sources are available in the analogLib library (i.e. vdc, vsin, vpwl, vpwlf, vpulse, vexp, and their current-generating counterparts). However, a single source called vsource or isource does the work of them all, and provides other advantages as well.The vsource (or isource) component is a multi-function source that can easily be configured to do the work of any of the above types of sources. Thus by using this one source, you can avoid the need to swap in and out different types of sources for different types of analyses, thus avoiding confusion and/or cluttered test beds.Another big advantage is that it "remembers" the settings that you give it, even when you switch to a different type of stimulus. For example, if you program a pulse, then switch it over to a sin or DC stimulus, the pulse settings will still be there when you come back to using it for pulses again.
Hi, I started using these sources, however I found one drawback. I can't get it to back annotate the DC operating point, while I can with eg. vdc.Is there some way to turn that behaviour on?
I don't understand - what do you mean by "back annotate the DC operating point?" - Hugh
After you have performed a DC operating point simulation using ADE you can enable the back annotation of DC operating points (eg DC current of voltage source) to your schematic by doing the following:in ADE: Results->Annotate->DC Operating PointsChris.
OK, I understand. No, I don't know how you might change it to cause it to annotate the dc op for the vsource or isource component. Maybe someone else knows a way?- Hugh
Looks like an oversight. The CDF for vsource doesn't have the operating point labels set.However, this is not an obstacle to using it. After doing the backannotation, go to Edit->Component Display in the schematic editor, select one of the "vsource" components, and select "parameter" on the form. Then in the three cyclic fields at the bottom you can choose v, i, pwr - and it will annotate those. If you save these settings away, you can make it always do this for this library.We really should fix the CDF for vsource and isource though. Later on I'll check if there's a CCR for that, and if not, I'll file one.Regards,Andrew.
Thanks Andrew,The workaround you propose lets me display the parameters that can be defined on that instance. If you select operating point for the parameter labels it says "No parameters of this type for this component". The same result is obtained when using the calculator (info tab->op).I can live with using the vdc source, but just wanted to give some feedback.Chris.
Sorry, I was a bit too hasty on my conclusion. Your proposal works!Thanks,Chris.
In reply to Ahmed Ammar:
Ahmed AmmarDear Hugh, I would like to have an idea about the different parameters for the source type "prbs" in vsource.
Please read the forum guidelines. They politely ask you not to post on the end of old threads - and this one was nearly 8 years old, and the author of the post has long since left Cadence.
If you want to find out more about prbs, consult the documentation that comes with the MMSIM release or the IC releases. In both you should be able to search for "prbs". You can also look at "spectre -h vsource" for some information, but you may find more in the MMSIM documentation. We provide the documentation for a good reason...