Precisely how does a BJT current mirror involve negative feedback

[matrixofdynamism]

I understand the idea of negative feedback when it is applied to Op-Amps. I have also heard that certain ways of connecting a BJT transistor results in a negative feedback effect on the transistor operation and this is also true for current mirrors made using BJTs.

How does negative feedback actually happen in a BJT current mirror?

 

[crutschow]

Since a current-mirror operates by the having the second transistor track the Vbe voltage of the first, it's not clear to me that it's negative feedback since there is no negative "feedback" from output to input. It is a feed forward loop.

 

[FvM]

If you like to, you can describe the operation of the diode-connected transistor as implementation negative feedback, but saying it's just a diode with larger area gives the same result,

Configurations like the Wilson current mirror are obviously implementing negative feedback.

 

[matrixofdynamism]

Can you describe how negative feedback then works in the wilson current mirror?