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.Originally posted in cdnusers.org by Hugh
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.