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Simulators >> Circuit Simulators >> difference between vdc and vsin component in cadence
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Message started by IanX on Apr 24^th, 2014, 7:40pm

Title: difference between vdc and vsin component in cadence
Post by IanX on Apr 24^th, 2014, 7:40pm

hello.

I have been confused for a long time. In analogLib, there are vdc and vsin. both of these component have the AC magnitude parameter.
In ac analysis, either of these component can be used.
What's the difference? Is it the same ?
I don't think so. But I can not tell the difference.
I guess one of the differences is that the frequency could not be set in the vdc component. Does it has a significant influence in dc or ac analysis since we can do frequency sweep.

thanks

Title: Re: difference between vdc and vsin component in cadence
Post by boe on Apr 25^th, 2014, 11:55am

IanX,
the difference is the behavior at transient sim: vdc is a DC source, while vsin is a sine source.
- B O E

Title: Re: difference between vdc and vsin component in cadence
Post by Andrew Beckett on Apr 26^th, 2014, 12:14am

They are both the same component in spectre. Both end up being vsource in the netlist. The reason for having multiple sources are largely historical. Many years back we (Cadence) added three comprehensive sources in analogLib, called vsource, isource, and port - which correspond more directly to the components in spectre. These then can access the complete (assuming they're up to date) set of features of the sources in the simulator - whereas each of the individual sources (vdc, vsin, vac, vpulse, vpwl, vpwlf etc) only give you access to a subset. Also, it makes changing a source from sine to pulse very easy - just a few parameters to change.

Regards,

Andrew.