# Output Impedance of a Wilson Current Mirror

Is the ideal output impedance of a Wilson Current Mirror 0?

Also, in the formula for the actual output impedance of Wilson Current Formula (i.e. R_out = [B/2]* r_o), what does r_o stand for? Also, what is the order of magnitude of a Wilson Current Mirror?

• $r_o$ represents the small-signal output resistance defined by the early voltage and the collector current. – KingDuken Mar 16 '18 at 2:18
• Think about it - ideally, it would have infinite output impedance, so no matter what load you attached to, the total impedance (and therefore current) would still be the same. Infinite + Load ≈ Infinite, so your current remains unchanged. – DSWG Sep 12 '18 at 0:37