Repeated - Introduction to Microelectronic Circuits - Exam, Exams of Microelectronic Circuits

Download Repeated - Introduction to Microelectronic Circuits - Exam and more Exams Microelectronic Circuits in PDF only on Docsity! Final EE40 Fall 2011 NAME: SSID: Instructions Read all of the instructions and all of the questions before beginning the exam. There are 5 problems in this exam. The total score is 130 points. Points are given next to each problem to help you allocate time. Do not spend all your time on one problem. Unless otherwise noted on a particular problem, you must show your work in the space provided, on the back of the exam pages or in the extra pages provided at the back of the exam. Draw a BOX or a CIRCLE around your answers to each problem. Be sure to provide units where necessary. GOOD LUCK! PROBLEM POINTS MAX 1 25 2 25 3 20 4 35 5 25 “Failure is always an option” - Disgruntled CS Guy (I assume he repeated this so many times to get on the final) Problem 1 Warm up (25 points) Consider the following circuit: In the box below, provide your answer in this form or LOSE POINTS (if there are extra equations, just write them in as well): ____v1 + ____v2 + ____v3 + ____v4 = ____ ____v1 + ____v2 + ____v3 + ____v4 = ____ ____v1 + ____v2 + ____v3 + ____v4 = ____ ____v1 + ____v2 + ____v3 + ____v4 = ____ ____v1 + ____v2 + ____v3 + ____v4 = ____ Solution: b) Now consider the case where we connect the following two modules together: Notice the first module is the same as that in a) and the second is very similar. Notice the two switches close on different conditions! If:  Vs(t) = VDD*u(t)  VOUT1(0) = VDD  VOUT2(0) = 0 Provide a SYMBOLIC expression for how long it takes for VOUT2 > VDD/2. (10 points) tVOUT2(s) = c) Repeat b) exactly but with the following slightly modified circuit. If:  Vs(t) = VDD*u(t)  VOUT1(0) = VDD  VOUT2(0) = 0 Provide a SYMBOLIC expression for how long it takes for VOUT2 > VDD/2. (10 points) tVOUT2(s) = "I don't see much sense in that," said Rabbit. "No," said Pooh humbly, "there isn't. But there was going to be when I began it. It's just that something happened to it along the way." -Winnie the Pooh Problem 3 DC Op Amps (20 points) Consider the circuit below. a) Provide a SYMBOLIC expression for (10 points) (So I thought of making the exam purely symbolic, but then the memegenerator post made me realize I couldn’t do this… so here are some numbers)  b) Assuming the following component variables, list the frequencies (in rad/s) of each zero in the transfer function. (5 points) R1 = 1 kΩ, R2 = 20 Ω, C1 = 5 µF, and C2 = 25 nF Solution: c) Assuming the following component variables, list the frequencies (in rad/s) of each pole in the transfer function. (5 points) R1 = 1 kΩ, R2 = 20 Ω, C1 = 5 µF, and C2 = 25 nF Solution: d) Assuming the following component variables, draw the magnitude and phase Bode plots in the semilog paper below. (10 points) R1 = 1 kΩ, R2 = 20 Ω, C1 = 5 µF, and C2 = 25 nF DO NOT FORGET TO LABEL THE X AND Y AXES OR YOU WILL LOSE POINTS! e) In THREE WORDS OR LESS, what does this circuit do? (5 points) _______________ __________________ _____________________ c) What is the bandwidth for this Q? (5.0 points) d) Change the value of one or more resistors in your design such that the circuit no longer oscillates. At what resistor value(s) is the boundary between oscillation and no oscillation? (5 points)