Physical Mechanism - Microelectronic Devices and Circuits - Solved Exam, Exams of Microelectronic Circuits

Download Physical Mechanism - Microelectronic Devices and Circuits - Solved Exam and more Exams Microelectronic Circuits in PDF only on Docsity! EBECSIO3 1 of 8 Fail 2000 Microelectronic Devices and Circuits- EECS105 Second Midterm Exam Wednesday, November 15, 2000 Costas J. Spanos University of California at Berkeley College of Engineering Department of Electrical Engineering and Computer Sciences Your Name: Otic tol So Letlons (last) (first) Your Signature: At Lo 1. Print and sign your name on this page before you start. 2. You are allowed two 8.5°x11" handwritten sheets with formulas. No books or notes! 3. Do everything on this exam, and make your methods as clear as possible. Problem 1 /30 Problem 2 /40 Problem 3 /30 TOTAL /100 EECSI0S 2 of & Fail 2000 Problem 1 of 3 Answer each question briefly and clearly. Sketch a simple drawing if it helps you make your point. (30 points) What physical mechanism limits the f.of a BJT? (6pts) Vara or oo. . The treaie thae of the valinky terlters ettuss the base. What is “base-width modulation” and how does it affect the behavior of BIT?(6pts) The wene -plawd BL Jenne has a lane ceolerion Pe g/ov2, At Ver Increases, rhe deplen an reylus Meereses hizo rhe base v0 Hive i¢ Shovter, TUS tnqeases Ie us @ dentirion of Veg rael rh gies the Tiesisor a now-jaliuire 9, balé-slynob cutut est ytagce). ‘You are given a 2-port, which has Rj,=1kQ, Roy=100kQ, and an open circuit voltage gain Ay = -10. Please draw the equivalent transconductance 2-port and calculate its Rij, Roy, and G,,. (6pts) , 4 Vout gy - ~ Gn Pout =? Vin bin Pout Vout Vin Guin J bm: je. Ie aigts Rat 1 Finz 449 Four: Joon? EECSI05 5 of 8 Fail 2000 » Sketch the 2-port Current Amp equivalent, and write expressions for Rin» Rout and A; Assume that 9 >> Rg: (10 pts). ‘ss ud ee, Actin Rove “aR 1 - = wl Rw = Qm A t Rout = Ce (tas) ¢) Calculate the overall (loaded) current gain, (note that Vps=0V). (LOpts) Rout : Rs ; = iin = Cs lowe =~ Orme WAS °F Rovet Re Ret Bia lout __ _ Rs st) Rout iS \Rge Rw /\ Rove ve = AW [aeiaes «(Gar sar TF 00) Zains =p = Im4 gw ~ af ) snl ox 0D 2 Raw = + = 900 Po * xi = GOTT * =R0kR AN = 7 = St au¢ = To (1 +9 s)s zk (lt gory San) = 30k Rov¢ = R 1 sok \: 433 930) z ( 220) BOER + SOON - (oe 3 lo q bout. — 9 328 ce EECSIOS 6 of 8 Fall 2000 d) You are now going to design part of the biasing circuit for this amplifier. The p-channel transis- tors transistors M, and My, have both the sameW/L. Find the value of Rye so that this current source delivers the 1mA of supply current that is needed (assume that the load draws no DC cur- rent). (10pts), W/L = 2000 7 Vap=-1V¥ a ppCox=25pA/V2 M a Isupply needed = 1mA / lynore eHerr f J Ven? . pl (W)(Veet Vee) | Leary Tret= Reet Zz R vet 4mA Let = Fsveply = \mA , A whe V¥s6,> ~Vrp 7%) = Ive aa z. ¢ Z. 2 Veg: [av Ve2 by ~Vse, =5V-V2V23,8V . Ve . 28V St Reef = ret Tonk 2 3.8k EECSIO5 7 of 8 Fail 2000 Problem 3 of 3 (30 points) For each of the following questions, make sure that you show the expressions before you plug in the specific values. A correct expression is worth 70% of the credit, even if the numerical calcula- tion is incorrect! a) Derive the transfer function Vout/Vin expression of the following amplifier (10 pts). C oo Vin hs es 2k, Te Ok -4 uF i F, IWRC, ee EE Lb (Folly )| =~ Gna = Vin Pat (i jutP.21) (it}WBG) time COMSTAATS : Tes Ad, = + Q: -, Gt fo 10 100 fo, 120d Isee GumP, > 40