UNIVERSITI MALAYSIA PERLIS. EMT182 - Analog Electronic I [Elektronik Analog I]

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1 <, UNIVERSITI MALAYSIA PERLIS Peperiksaan Semester Kedua Sidang Akademik 2013/2014 " 13 June 2014 " EMT182 - Analog Electronic I [Elektronik Analog I] Masa : 3 jam Please make sure that this question paper has ELEVEN (11) printed pages, including this front page and Appendix, before you start the examination. [Sila pastikon kertas saolan ini mengandungi SEBELAS (11) muira sural yang bereetalr, termasuk muka hadapan dan Lampiran, sebelum imda memulakon peperiksaan ini.] This question paper has SIX (6) questions. Answer any FIVE (5) questions only. Each question contributes 20 marks. [Kertas soalan ini mengandungi ENAM (6) soalan. Jawab mana-mana UMA (5) soa/an sahaja. Markah bagi tiap-tiap soalan adalah 20 markah.] Dicetak oieh Unit Peperiluaan & PengijamJran, Bahagtan Pengurusan Akademik, Jabatan Pendajttu.

2 Question 1 {Soa/anl{ -2- The transistor Q 1 shown in Figure 1.1 has 13 = 100 and early voltage, VA = 00. Assuming that RJ = 10 ill, R2= 50 kn, thennal voltage, VT = 25 mv and emitter-base voltage, VEB = 0.7 V, answer the following questions: [Transistor QI yang ditunjukkan da/am Rajah 1.1 mempunyai P = 100 dan voltan awal, VA = '" Dengan mengandaikan RJ = JO kn, R2 = 50 kn, valtan haba, Vr = 25 mv dan va/tan pemancar-tapak, V ~ = 0.7 V, jawab saolan-saolan beriwt:} Identify the type of transistor Ql. {Kenalpaslijenis transistor Ql.] '. (2 Marks! Markah) (b) Plot the Q-point on the de load line. {Plotkan litllr-q pada garis-beban arus fetus.] (8 Marks! Markah) (c) Calculate the following small-signal parameters of transistor QI; transconductance, gm, input resistance, r. and output resistance, roo {Kirakan isyarat-isyarat lwei/transistor Ql berilcut; Iwaliran transistor, g.. r/ntangan mmukan. r. dan rintangan Iwluar, r~} (3 Marks! Markah) (d) Detennine the small-signal voltage gain [Tentukan gandaan voltan isyarat Iweil.} (7 Marks! Markah) Vcc=+12V v, Figure 1.1 {Rajah 1.11 Dicelak oleh Unit Peperiboan & Pengijazahan, Bahagian Pengurwan Akademik. Jabatan Pendaftar,

3 .. Question 2 /SoaIan2/ (EMTI82) Sketch and label the physical structure and the standard symbol of a npn Bipolar Junction Transistor (BJT). {Lalll1r dan labellll1n strukjur jizilll1l dan simbol standard Transistor Simpang Dw;kulllb (BJl) npn.}. (3 Marks! Marlll1h) (b) Figure 2.1 shows a biased common-emitter amplifier for operation at almost constant base current, lb. Assuming thermal voltage, VT = 25 my, early voltage, VA = 00 and emitter-base voltagll, VBE = 0.7 V, answer the following questions: (Rajah 2.1 menunjulrjran penguat pemancar-sepunya yang dip;ncanglll1n unlllk operas; ~ arus tapak, I. (humpir) tetap.' Dengan mengandailll1n voltan haba, V T = 25 mv; voltan awal, V". = Of) don voltan tapa/c pemancar, V BE = O. 7 V; jawab soalan-soalan berikut:} (i) Calculate the value ofrb so that the quiescent output voltage, VOUT = 3 V, for a BJT with f3 = 100. {Kiralll1n nila; R. supaya voltan /celuaran tenang, V OUT - 3 V; unlllk BJT dengan p= l00.} (8 Marks! Marlll1h) Determine the small-signal voltage gain for this amplifier. [Tenllllll1n gandilan voltan isyarat /cecil bagi penguat ini.} (3 Marks! Marlll1h) (iii) Assuming Ro has the value obtained in 2(b)(i), colculate VOUT for BIT with f3 = 50, and BIT with f3 = 150. (Andaikan RB mempunyai nilai seperti yang diperolehi dalam 2(b)(i), kirakan VOUT unlllk BJT dengan P = 50, dan BJT dengan p = 150] (4 Marks! Marlll1h) (iv) Conclude your answers obtained in 2(b)(i) and 2(b)(iii). (Simpul/canjawapan-jawapan anda yang diperolehi dalam 2(b)(i) dan 2(b)(i1/).} (2 Marks! Marlll1h)....4/- Dicetak oleh Unil Peper/baan &: PengijazaMn, Bahag;an Pengurusan Akodemik, Jabalon Pendaflor.

4 -4- +6V Rc=lOkQ Figure 2.1 {Rajah2.1J " Dicetak oleh Unit Peperiksaan & Pengijazahan, Bahagian Pengurusan Akademi/c, JaOOtan Pendaftar.

5 Question 3 {SoaltJII Jj - 5- (EMTI82) List TWO (2) basic characteristics for Junction Field Effect Transistor (JFET) and Bipolar Junction Transistor (BJT). {Senaraikan DUA (2) eiri asas!intuit Transistor Simpang Kesan Medan (JFET) dan Transistor Simpang Dwiladuh (BJT).J (4 Marks! Markah) (b) Based on the JFET amplifier circuit shown in Figure 3.1, [Berdasarkan litar penguat JFET seperti ditu'1iukkan dalam Rajah J.l.} (i) calculate the quiescent value of gate to source voltage (Y GsW and the transconductance (gm)... [kirakan nilai tenang bagi voltan get lrepada punca (Yosg) dan lrealiranpindah (g"j.j (4 Marks/ Markah) calculate the voltage gains (Av), when Rs is bypassed and unbypassed. [kirakan gandaan-gandaan voltan fa'), apabila Rs dipiraukan dan tldak dipiraukan.} (iii) sketch and label the transfer characteristic for the amplifier. [Iakar dan labelkan eiri pindah bagi penguat tersebut.} (4 Marks! Markah) (2 Marks! Markah) (c) N-channel JFET is operated under reversed-biased condition where the field effect is controlled by applying drain supply voltage at the drain tennina!. [Saluran-N JFET beroperasi dibawah lreadaan terpincang-mundur di mana lresan medan dikawal dengan mengunakan voltan saliran bekalan di pangkalan saliran.} (i) Predict what will happen to the transistor when drain to source voltage (Yos) is increased beyond the saturation region. [Ramalkan apa yang akan berlaku lrepada transistor apabila voltan saliran lrepada punca (Vos! meningkat melebihi kawasan lretepuan) (2 Marks! Markah)... 6/- Dicetok oleh Unit Peperi/csaan & Pengijazohan, BaMgian Pengunuan Akademik, Jaba/an Pendaflar.

6 - 6 - By using your own words, explain briefly why pinch-off happens at the drain region when drain to source voltage (VDS) is increasing for constant Vos. [Dengan mengunakan perkataan sendiri. terangkan secara ringkas mengapa jepitan berlaku di kawasan saliran apabila voltan saliran kepada punca (V m) meningkat untuk Vas yang kekal.] (4 Marks/ Markah).. IDss = lorna VOS(oft) = -3.5 V IDQ=2.4rnA Figure 3.1 {Rajah 3.1] Dicetak oleh Unit Peperiksaan & Pengijazahan, Bahagian Pengurwan Akademik, Jabalan Pendaftar.

7 '. Question 4 {Soaian To use the circuit shown in Figure 4.1 as an amplifier, the transistor needs to be biased with dc voltage at quiescent point (Q-point). With the aid of a diagram, explain briefly the meaning of Q-point. {Untuk menggunakan litar yang ditunjukkan dalam Rajah 4.1 sebagai penguat, transistor perlu dipincangkan dengan voltan arus terus pada titik tenang (titik-q). Dengan bantuan gambarajah, terangkan.ecara ringkas maksud titik-q.] (4 Marks! Markah) (b) A common-source N-channel Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) amplifier with A. = 0 is shown in Figure 4.1. Given the quiescent values, IDQ = 6 rna, VGsQ = 2.8 V and VosQ = 10 V. The transconductance, g.. = 2.2 rna/v. Assume that RL = I ill, Rin = 100 ill and voltage gain, Av =-1. [Satu penguat Transistor Ke.an Medan Logam-Oksida-Semikanduktor (MOSFET) punca-sepunya saluran-n dengan A = 0 ditunjukkan dolam Rajah 4.1. Diberi nilai tenang, IDQ = 6 ma, V asq = 2.8 V dan VDSQ = 10 V. Kealiranpindah, g", = 2.2 malv. Andaikan RL = 1 k.q R 'n = 100 kndan gandaan voltan, Av = -1.} (i) Sketch and label dc equivalent circuit for Figure 4.1. [Lakar dan labelkan litar setara arus teru. bagi Rajah 4.1.} (4 Marks! Markah) (il) Determine the values of Rl, R2, conductance parameter, K and threshold voltage, VTN. [Tentukan nilai Rio R J/,s, RIJ, parameter kealiran, K dan voltan ambang, VTN-} " (12 Marks! Markah) Ru._i, i ~---jl-_-o Vo V; Figure 4.1 {Rajah 4.11 Dicetak oleh Unit Peperiksaan & Pengjjozahan, Bahagian Pengurusan Akademik. Jabatan Pendajtar.

8 ,, Question 5 [SoalaIlS} Sketch and label the Q-point on dc load line for class-a, class-b, class-ab and class-c power amplifiers in the same figure. [Lakar dan labelkan titik-q pada garisan beban arus te17ls un/uk penguat-penguat kuasa kelas A, kelas-b, kelas-ab dan kelas-c pada rajah yang sama.] (4 Marks! Markah) (b) llustrate the output waveform of class-a, class-b and class-ab power amplifiers according to the time percentage that the output transistors are conducting. [flustrasikan gelombang keluaran bagi penguat-penguat kuasa kelas-a, kelas-b dan kelas-ab terhadap peralusan masa bagi aliran keluaran transistor.} '. (6 Mirks! Markah) (c) A class-b power amplifier as shown in Figure 5.1 can deliver an average power 000 W to a 6-!l load. [Sa/u penguat kuasa kelas-b seperti di/unjukkan dalam Rajah 5.1 boleh memberi kuasa purata sebanyak 30 W ke sua/u beban 6 ell (i) Calculate the required value of supply voltage, Vee if the peak output voltage, Vp must be no larger than 80 % of Vee. [Kirakan nilai bagi voltan bekalan V cc yang diperlukan jika puncak voltan keluaran, V. mesti tidak melebihi 80 % daripada V cc..] (2 Marks! Markah) Evaluate the peak current in each transistor, Ip, the average power dissipated in each transistor, PQ and the power conversion efficiency, 1"]. [Nilaikan arus puncak bagi setiap transistor, fp, purata kuasa lesapan bagi setiap transistor,pqdan kuasa kecekapan perlukaran, ".] (6 Marks! Markah) (iii) Propose a technique to overcome the problem of cross over distortion in Figure 5.1. [Cadangkan sa/u teknik un/uk mengatasi masalah herotan lintas dalam Rajah 5.1.] (2 Marks! Markah) Dice/ak oleh Unit Peperiksaan & Pengijazahan, Bahagian Pengul1lsan Akadem;k, Jaba/an Pendaftar.

9 ovo v- '. Figure 5.1 {Rajah 5.11 Dicetak oleh Unit Peperiksaan & Pengijazahan, Bohagian Pengurusan Akademik, Jabatan Pendaftar.

10 " Question 6 {SOIl/an 6} With the aid of current-voltage curve, discuss the characteristics of the following devices: [Dengan bantuan lengkung arus-voltan, bincangkon eiri-ciri peranti-peranti berikut:} (i) Standard diode. [Diod standard} (3 Marks! Markah) Basic thyristor (Shockley diode or also known as 4-layer diode). f'xhyristor' asas (diod Shocldey atau dikenalijuga sebagai diod 4-lapi.an).] (3 Marks! Marlwh) (b) Silicon-Controlled Rectifier (SCR) is another type of thyristor. It consists of 4- layer pnpn similar to the 4-layer diode, except with three tenninals i.e. anode, cathode and gate. [Penerus terkawal-sililwn (SCR) merupalwn salah satu jenis thyristor. [a mengandungi 4-lapisan pnpn hamper sama dengan diod 4-lapisan, kecuali ia terdiri dari tiga terminal ialtu anod, lujtod dan get.} (i) Construct and label the basic structure, equivalent circuit and currentvoltage characteristics curve. [Bina dan labellwn strulrtur asas, litar setara dan lengkung eiri-eiri arus-voltan.} (6 Marks! Markoh) Point out the operation of SCR based on the current-voltage characteristics given in 6(b)(i). (Tunjukkan operasi SCR berdasarlwn poda eiri-ciri arus-voltan yang dlberilwn pada 6(b)(i).} (8 Marks! Markoh) Dicetalc oleh Unit Peperiluaan & Pengijazahan. Bahagion Penguru.ran Akademik. Jabatan Poulaftar.

11 ,. - II - APPENDIX (LAMP/RANI Some formulae for Bipolar Junction Transistor (BJT): [Sebahagian formula untuk Transistor Simpang Dwjlcutub (BJI').) r. = v... oleo Some formulae for Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFE1): [Sebahaglanformula untuk Transistor Kesan Medan Logam-Okslda-8emjkonduktor (MOSFEf).} Some formulae for Junction Field Effect Transistor (JFET): {Sebahagianfomnlla untuk Transistor Simpang Kuan Medon (JFET):] Dicelak oleh Unit Peperiksoan & Pengijazahan. Bahogian Pengurusan Akademik, Jabolan Petuklftor.

UNIVERSITI SAINS MALAYSIA EEE 241 ELEKTRONIK ANALOG I

UNIVERSITI SAINS MALAYSIA EEE 241 ELEKTRONIK ANALOG I UNIVERSITI SAINS MALAYSIA Peperiksaan Semester Pertama Sidang Akademik 2009/2010 November 2009 EEE 241 ELEKTRONIK ANALOG I Masa : 3 Jam Sila pastikan bahawa kertas peperiksaan ini mengandungi LAPAN muka