Come on Josh, I know that...

But some devices are intended to have very low impedence voltage supplied to the pins as signal, and some are responsive to a stiff current source that provides whatever voltage is nec. to supply the 'signal' current. This was clearly the intent of the question.

Of course there is no way to use a voltage without some current involved, and current won't flow without some electromotive force to move it.

(If answers need to be this in depth . . . )

Brian