# q07 - f ect can be neglected i.e V A = ∞ Making use of...

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ECE3050Ana logE lectron icsQu iz7 February 25, 2009 Professor Leach Name Instructions. Print your name in the space above. Honor Code: I have neither given nor received help on this quiz. Initials 1. The f gure shows a basic two-BJT current mirror. (a) Assume the two transistors are identical and that the Early e f ect can be neglected, i.e., V A = . Label the branch currents and derive the equation for the output current I O . (b) If the Early e f ect is not neglected, what would be the output resistance r 0 ? I REF = I O + I O β + I O β = I O = I REF 1+2 r out = r 02
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Unformatted text preview: f ect can be neglected, i.e., V A = ∞ . Making use of the results of Problem 1, label the branch currents and derive the equation for the output current I O . (b) Aside from the di f erence in the equation for I O , what is the major di f erence between the Wilson mirror and the two-BJT current mirror? Make use of the answer for Problem 1 to solve for I C 2 . I REF = I O β + I O /α 1 + 2 /β = ⇒ I O = I REF 1 β + 1 /α 1 + 2 /β The output resistance is much higher than for the two-BJT current mirror. This is caused by a positive feedback e f ect. 1...
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## This note was uploaded on 05/26/2011 for the course ECE 3050 taught by Professor Hollis during the Summer '08 term at Georgia Tech.

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