[SOLVED] Why do we need to use Vdd in a current mirror ?

[alikemal]

Hi
I am new about current mirrors and i dont understand why we need to use Vdd ? because we already use a current source.

 

[alikemal]

So if i dont use Vdd in a simulation, what will happen?

 

[FvM]

If you assume that the current source has an internal energy source (an ideal current source in a simulation of course has), you don't need Vdd. A technical current source, e.g. a transistor circuit will need an external energy source.

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No difference at all.