Quiz 8 on Microelectronic Circuits - Question | ECE 3040, Quizzes of Electrical and Electronics Engineering

Download Quiz 8 on Microelectronic Circuits - Question | ECE 3040 and more Quizzes Electrical and Electronics Engineering in PDF only on Docsity! ECE 3040 Quiz 8 — July 13, 2005 Professor Leach Name Instructions. Print your name in the space above. The quiz is closed-book and closed-notes. The quiz consists of one problem. Honor Code Statement: I have neither given nor received help on this quiz. Initials 1. The figure shows two common-emitter stages in cascade. It is given that RB = 1kΩ, RC = 10kΩ, IC = 1mA, VCE = 10V, VA = 40V, VT = 25mV, β = 99, gm = IC/VT , rπ = VT /IB, re = VT /IE , and r0 = (VA + VCE) /IC . (a) What are the values of gm, rπ, r0, and re? gm = 0.001 0.025 = 0.04 S rπ = 0.025 0.001/99 = 2475Ω re = 25.25Ω r0 = 50kΩ (b) Draw the π model for the two transistor circuit. You must use this circuit model to solve for the following three parts. Credit will not be given if any answers are written from memory without their derivation from the circuit. (c) What is the value of vb2/vi? vb2 vi = 1 RB + rπ × (−β)× r0kRCkrπ = −54.37 (d) What is the value of vo/vb2? v0 vb2 = 1 rπ × (−β)× r0kRC = −333.33 (e) What is the value of vo/vi? vo vi = vb2 vi × v0 vb2 = 1.812× 104 1