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Emerging Domain in Electronics Engineering (Sem-1 & 2) 1 Béiton : 2020.21 So === CONTENTS KEC-101T / KEC-201T : EMERGING DOMAIN IN, ELECTRONICS ENGINEERING UNIT: : SEMICONDUCTOR DIODE (1301-475) ‘Semiconductor Diode: Depletion yer Vl characteristics, de and psc Diodes Diode gla css, Zener Ddesbeahdown mecha net sraavaiin Diode Application: Dinde Configuration, Hal and Full Ware esfcaton, {pps Clanpers Zener diodeas Shantou, Vokage Nelipie Casas Special Purpors vo terminal Devices pvt Eniting Bas, Pato Dade, Varaclor Diodes, Tanne Diodes Ligil-Costl plays UNIT2 : BIT AND FET (213t02-385) Biglar Junction Transistor Tansnr Connon Operation Arnlicaon| ‘con Common Sse, Cammon Emer Common Calicios Contgvion. Feld Efe Transistor Contrseton and Characerate of FETs Taster (Churcterisic, MOSFET (M105) (Deleon an Eataneement Type Teale Charcot UNITS: OPERATIONAL AMPLIFIERS ANDIOT —_ (8-1 J103-303) Operational Amplifiers ntrurten, Op Amp asc Pca Op Amp Cas Aitverting Arspiier, Non-inverting Ampie, Unit Follower, Scnining Aspiie ntator, Dilerntatr)Dierenia and Common Mas Opes Comparators Introduction off System, Components of oT syste: Mioprocesor ond Microcontoter, Blictooth Technology, Wi-Fi Technology Coneep of vy _ Networking Sncgy Nodes, concept lo, UNIT-4 ; DIGITAL ELECTRONICS AND ICT (414%04-153) Digital Electronics: Numberoytem representation Itroducton of Baie sd Universal Gates, sing Boca alg pinta of Boolean hrc, K’Map Minimization uploe Varatle Introduction ToIC Technology SI MS, LSL VLSI Integrated Ces. UNITS : FUNDAMENTALS OF COMM. ENGG. (G13 t05-30) Fandamenislsof Communication Engineering Basse Spraligrecrenson ent sls Ectomugesespecrum ElanentsalsComaninzaton Stan, Neo ‘modulation and typical appt, Funds ofamplaccmeubtonest enodutston Intoducionta Data Communications Gk snd appcatonset Newark General Mode! of Wireless Communication: Pvoluien of mabe radio ‘communion endamantas GPS, CSM, COMA Emenee Rade Consmsicasn SHORT QUESTIONS (6Q.1410SQ-219) ‘SOLVED PAPERS (2015-16 TO 2017-18) (ODD & EVEN) (SP-1JtoSP-243)‘Semiconduetor Diode : Depletion Layer, Vl Characteristics, eal avd Practiea! Diodes, Diode Bquivalent Circuits Zener Diados Break doven xn Mechonism (ener and Avalanche) Diade Application : Diode. Configuration, Half and Full Wave Rectiiation Chippers, Clampers Zener Diode as Shunt Regulator, Voltage-Multiplier Circuits Special Purpose Two Terminal Dovies : Light Emitting Diodes, Photodiodes + Varacter Diodes, Tunnel Diodes, Ligoia-Crytal Displays 1 | Semiconductor Dade 5 Senconductor Diode: Dipickon Lever Vi\Characiernice © “Tiel ond Prostia! inden, Diade Bqutotent Oreuns — (ie [7g Rage t9p anahioden Anrve yp oc Qaoti] Explain coquivalent cireut. ronductor diode and also draw its Taswer 1 Aiodeis an electrical deve slowing caret to fw oly none direction (forward bias) with far greater ease than in the other direction (revere bias). 2 ‘The mast common type of diode in modern cireult design isthe semiconductor diode (pn junction) 3, Adiode a two-layer semiconductor consisting of p-type semiconductor Inaterial and n-type semicondctar materia the equivalent creit of diode ie shownin Fig 1.1 Sich Ao —_Dp-—28 io es Diode symbol Equvaebt erat mae) 4. Inancquilibrium,p-junstion, the ree electrons fr the n-ype region twill dtfaseserose the junction to Uh p-type side where they weil Tecombine with some of the holes in the p-ype material. Similars, Toles wl diffuse serovs the junction in the oppesit direction and recombine. 15. ‘Tho recombination of free eleetrons and hols in the vicinity ofthe jJuetion leaves narsow region either side ofthe junction that ‘ontalns to mobile charge Thiemarrw region which has ben deleted ‘tmaile charge sealed the depletion layer. 6. Diffusion electrons int tho pein willleave positively charged ions (onore inthe w-region. 11. Similarly, diffusion of les nese the pn interface in th n-type region Teawo fixed ions oceeptors) with negative charge,sin in Electrons Engineering 285 nei Do ‘ay, reson nary the - interfceslose thelr neutrality gag 8 Bere ing he ec carg® 40 or depletion age oom som | woe | < Ne fone fee | Pt enn “Fig 1.2: p juletion semiconductor, | ‘&Thisseparation of charges causes an clectre fed to extend arose depletion layer A potential difference must therefore exist acts eplation ager ‘i ‘Goi | plain the V1 characteristic of pon junction diode, Deaw well labelled characteristic. i [RTO ROIETT Gombe 1 Forward bis: 1. Farthfoardhiasofpnjunton, p-type connected tothe it ternal wilh mye tong trial fate 2 Thoptentalcanbovarin with ential vider. At some forward 6G vr tangrereaats oe hoa ‘erent starts fling. Ths valtage i known a8 thresbld 2 vole sate 2 4 Asthefoorard stage ppd inerases yond thresold eh fsceard current ser exponentially ac chown in Fg 12 ‘Boy certain safe alae, it produces an extremly ‘whl ny destroy the jancin dae to avert te Retina dsb ct dat reo The p-ype is connected to ie we the negative terminal wile crane the postive termina ire terminal ofa battery. nee sa 2 intense the ee ‘nth cas the junction reitance becomes very Bh © reat owe trough the cnet ss 145 emi 82 ‘Semiconductor Diode {3 Inproctcal,aemallcurentofthoordr af pA flowsin the circuit eto nino cariors This oknown ae reverse caren The reverse current Feshown nig. 121 yma 44. Asthe reverse bis ixinrensed from ero the reverse current quikly ‘te tate manimm oreataatin value. The slight increase is eo ‘Eepurtes onthe surface, which behaves ata resistor and hence ober tums nw This ive ie to @current called surface leakage eurret. 5. Ithorovers voltages fart ineenced, the kinetic energy aletrons ‘becomes so high hat thy kneel out from the semionduetor toms. At {his stage, breakdewa of junction occurs and there isa sudden rise of| reverse urrent, Now te netion is destroyed completly {6 Thus, pon junction diode is one-way device which offers low reitance ‘ren forward isced and behaves ike sn asuator when reverse biased ‘Thus, canbe ued as arttifier efor eonvertingaltemating current Into direc urret. wen characteristics of a p-n junction diode, AL Ideal Vs characteristic: 1L_Antdeal ind is porfct conductor in forward bias and aperieet resistor inreverso bins 2 ‘The current-voltage characteristic ofthe ideal diode is shown in Bg 1S Sketch and explain ideal and practical V-IEmerging Domainin Electronics gineering __‘-8I¢SOM1&2) 4.6 5 (Gomme 82) Semiconductor Diode 1p 44 The bility of diode a withatand reverses vllgeiimied the sppliedreverac-bis vatage becmes too lang dnd wl experience a hhevy condution known ar reskdown, whic uualy dente '5 ‘The currnt vermuvaltage curve fora reel diode okie ae shir in Re 13a Ya Ve (ParT2] Zener Diodes Breakdown Mechanlam (Zener and Avolanch) he Fig, LLL Vaart a ea ide 8. Aiode acs as sort circu whan it ie frward biased. When itis | ‘everseblased, carts esanopen eeu. | 4 Thre onde neat ruta reek Nopovere dite | Per SELES carat Soecinheran dretio, | QaR0A sraterietio orn ontion diode He Raa cesta tise destin: onde reese icin aiterfom ene ote? [AETORTET? Semi] B. Practical: = BPE tao ithe somal intvaage (Vintner | Explain fputand output characteristic ofzner oe Ets iy tte etapa ys RTOS a eas aS emicondurtor sod ins porjuntion bt eannot be measured diet maa A. Vl characteristic of pn junction diode Refer Q.L2, Page 1-3, Unie B, Zener diode: 1. Zener dodo a revere biased bevily doped pn juntion diode which {operated inthe breakdown ropa, Fig 1-4 shows the symbol of ener dnd, es igen nase te || 2. Whena zener diode forward biased ts chractorstics are just same ts tho ordinary diode anata shown in Fig. 1.42 2 The resistor approximates he semiconductor resistance hen diode is (ON/OFF or forward bias teverse las {When eer die incerreed thetssonancurent Pe 8. Arevers biesod diode conduct ‘ecrainvellage. When the reverse Blas voltage is inerened beyond biased diode conducts very small amount of curren ealed that vellage the current nereaed rapidly asshown in Big. 14.2. leakage curront1 Zenerbreatidown: j 4. takes plein very thin junction, depetio aye ianarrow eto ‘2 Whonaamal reverse ins olago applied very strong electric fd 4 Thisteldisenough tobeaktheenvlent bonds. Thisbreaking of covalent Emerging Domain in Hlectronies Bagineerinig ima Vy VE lo ” 1 ig ve area ar ae 4. Thecatottvale of voltage beynd whi ener dade revere carent [neremor pip called ene vltage Vor breakdown alge. The breakdown or ronervliage depends upon the smut of doping. 6 Asner id on be ad ar voltage eultr to provide constant ‘ellos toa lea ._Diference: S.No] p-rjunetion diode Zener diode 1. | he electri lows in one | Te lectrict fows nth the dein direction 2 |The Vias] The reverse bias makes the Permanently damages the|eletsiity flee in both the Sepltion reo, Airetion & [The width of depletion) The width of depletion regione repos lage becnuse ie p| narrow Because the p snd m Seen shy dope | regione heals doped “4 [Thisisusdiurreciieation |This ie sed for voltage regulation {9ETB | Pepin reversebreakdown ofa diode. ieee] | ee ‘breakdown and avalanche breakdown. . : a Ieavly doped janet th eel Capproximstey 107 Vin) ist up eros he thin deplete | ‘bonds produces large number of electrons and holes which conet | ‘Teverse auturation current (i.e, ener current). = ee Semiconductor Bode 1-85 Gem &2) 44 Zener caront independent of he appli voltage It depends lyon (ecxtomal resistance {This brew iclled aa tener bresdown a thown in Fig. 1.8. ‘Thera oecurs at law vleage 1 Zane breton Asatte bakin | pRETneLraamaarempnaa) eo IL Avalanche renidows 1. alec treldwn apace ht hk junction than the ‘Mrerelonn cn Temeanbethide uni righ dpe 2 niacin, thelr depletion repo ayia 2 roo ruc tmr alow forte soe plied lage of ‘nor beaidown ese 4 Hor, the minty rir seated hy he ld eae withthe Semicond stomein th elton exo. 4. Dering caivon the Kntc ners leone tented other Corl ahah neg eared cles ines Shean ne, hens event bonds ee braen a tone perarsemottd 5 The nony goed caries tras thi energy to ter colt ‘unin nds tr exe ne ani fees {Deena noc ra oavloto ation Thisbresdwn called svlach reskdown a hownn Fig 192 ‘is reahdown cose a her vlogsEmerging Domain in letroncs Engineering ‘1-95 emt 82) 1-105 em-1 2) Semiconductor Diode GeTAT | Explain th series diode configuration Tamer | 1L. Theserioscieuit of diode is shown in Fig. 16. 6 The dade is inthe “OFF” stato, esling in the equivalent ere of 2 Theta ofthe dens determined by replacing the ode with etait ‘osstve lament os shown in Fig. 6a) Testing cretion ois oe e TRESS inc crow a te dedespmbol and since E> Vqte diode Det opn iret the diode currents A andthe voltage aro the cee rataee resistor ic thefliowing ) with the [gR=[pR=(0A)R=0V ‘3. The network is then redrawn os shown in Fig, 1.6.26) {pproprat equivalent nde! forthe oreard bisedsiicon dade. J "y. (Pig. 1.641; Series diode configuratic | a 4. The resulting voltage and current level are the following. | eas Yen "e Determine Vo, and draw the output waveform of the Wye B-Ve given network of Fig. 1.7.1. ai Ye i Iyelee ov res [ARTO BOT Taso, MSO] tower] mene ree 1 or¥,5V, the diode is reverse-iased and Vo Yo 0. 1. Assume input waveform, "i of eye 4° gun Vor 02¥ Voltage across 80, applying KVL ino es: 2. Por pasivebalf ele ide iin ON tate = Ave10¥=02V-07¥=0 eid / v,=86V. 4. ornate lfc Did isin OFF tte, ‘ Yor—42¥j2n4-8=-2V | wenme, ye Ho 88Y sora 4. Output waveform se thown in Fig. 183 754 "o b= ary ‘Apply KCLat node Iy=,fy= OTS mA—O.1167 A | ‘e098 m8 % the working of hale wave and full weve Bridge Expl— 1-199 emt 82) ‘Bering Domain in Bectronits Bogincein ae wai a | eMsGeneD Semiondortor Dido on Explain the beige rectifier with clear diagram 1 Conter-tap retifier: (aierC aOrTIsCSemD, MPR 3) Ed age rect ‘Druw theelrnit and discuss the working full wave Bide rectifier) ‘with suitable inputowtput wavefor oe (aa DOTOATISomeD, Mar acraage Bu SS al be retifer: stor nF 1103 As th ome ee A ar et gre cer ste hore. cote rw omer ae re ome ve (ig: 1.103: epg OURS 2. temerifr Tepe ion eto meter! ‘used for it: | 2 Incentertap ful wave rectifier rei ide Dy Ialreyce Oto) and the dd D, willbe OFF daring hye “The diode D, ll bo ON for negative half eee i, to 20 while the inde D, wil be OFF during this ele. ‘The input and ostpat wavalorm are shown in Fig. L104 [Bcidge rectifier: As shown n Fg 110.5) nly odes Dy ae D, are ‘tive during poiive ball eyle whl odes Dy and D, ae active for ‘egative bal eel as showin Fig. 110. and Pig. £10. shows ‘he totel ouput wih the activ dios fora partcla pele.os ngneing 1181 sing Dann eco ig) 10 an eg eer ale | outlet rec for postive alee, {o Outpt of ge rier restive bale OND Soret alee | ‘Fae TAI] Explain the following trms in context with half wart | ‘rectifier and full wave rectifier: | ADE voltage and DC current fi, RMS value of current on ‘Fors half wave rectifier, derive an expression for ripple factor: (ARTO ROE T6 Semi, Marks 1164 emt £2 Semicondyetor Dido on E> 5 -2BE “Br | 28 56 Fe geese fii Positive pulse of V, Diode‘ON'and Vy=-2V+0.7V=-13V Capacitor charge to 10V+2V-0.7 V=113V Negative pulse of V, Diode‘OFF’and V)=—10V-113V=-213V ¥, asv 213 ‘Qiie 120; | Define olipper circuit. Sketch the output waveform for the circuit shown below given input.a Semiconductor Diode ce 10a ¥.=07-63 tye Me a 4 Pas ka“ i0Eo ce sav wien204) rarer Bor Samy ark 07) ‘Clipper: Refer @ 115, Page 1-2, Unit y Nemerial: it During postive halfeyce of: TL WhenO2, <6 thenbuth diode, ‘utp wil lo inpt vase Tow Bev 25.6, thon, willbe forward biased and D, will and D willbe reverse biased and 2, Wien be revero Based So, Vox 07453 =5V onstand 13, The current ig wll Dow only when either of the two diodes will be warded. 4 H ‘gran 4. For, =10V During negptive ha evel of V, Sve vo, ot dade wil reverse bined so output wit fallow inpitolage i, Ve ‘hen ¥,2-8¥ then By wl Uased v, Ibe reverse ised and D, wile forward Se, Vor =(07+63)=-8V(consant) Fe veEcaov Yur07 078-1048 __ 59, tne Sona" Ton ~97™ ‘the waveforms forV, ay te shown in Fig. 1.202 GASTAT] waplain the unetion of the crest of Fig, L.2- and draw the output waveform. 15sin ald 1. During positive halfrcte 1 Casets When ¥<8V ‘Diode A ond bare revere bond Vor Va te casea: When Va 26% (Gate osward aed lode Bis revere biased ¥pe 8 2 Daring negative half ele: BE Gaged When Vg <—9¥, ‘ade and blir revere based Vo= Vi, fh Cason: When Vg ae ees ised, ide Bis forward biased yey Fig, 1224, =] vor the given clamper cirouit shown Qantas and azo draw the waveform of output determine the oxtput voltage Sienal‘Emerging Domain n Blectronice Engineering La1s Gomi & 9) | saisecntan ALE ae == oT uring postive ple of Vth inde ie hort druted. Te voltage ‘scrawl beth same a seront thebattery (paral So, Y= 5V 2 Theveltage that cage pth capacitor, pplying KVL ‘T10V-V,-6¥= 0 then = 8 3. During negative pals of the diode isopen circuited, Applying KVL, Voge i= 5=—20V PART-S. Zener Diode as Shunt Ragulator, Voltage Multiplier Circuits, QEeTRE] tow zener diode in uae a shunt regulator? Explain 1. The cee diagram ora Pg 123, nervoltagelshunt regulator circuit is shown? Semiconductor Bode 2 The zor dio ial wi an Teo th V, ema tothe eta deed 4 Under revre ited onion voltage con zene die peat ene constant, even i the cure tnough changes ea Une normal onions th int erent =f +1 ‘esstrR. Th apt vlige Vente write ag" = 1™¥™ St Vey Retnd, eRe e, |e ge 281 Zane wtp at 5. When th input voltgeV, nereats a the oliag across ener diode ans constant, the drop crosewlinease with ecoresponng fnereac inf» 6. ABV, loacontan hevotag acon the nd willako remains cata tnd hence, willie aconstant 1 Therelre acres in, wil osu in ences ind which wi ‘otalter the voltage serotlosd Tus zener dad inused aa age 8 Thoperate ene diode a oa regulator, the reverse voltage appt toaener dade never exeods PIV othe dod nd athe same i, he pied input voltage mst be greater thn the breakdown vliage of the ener dod quer] i. Find th range of Rand, that will maintain a constant output of 10 V (Fig 1241. ‘Also determine the maximum wattageratingof the zener diode [Rae woHe Seon a7]Emerging Domain in Bloctronies Engineering 1-830 (Sem-1, wer’ Given, .,=92mA, V,=10V ‘To Find : Range of J, and R,, maximum wattage. 3 1. Fromthecireuit, T= ,+1, =V, _ 50-10 wher, YY, - 80-10 49 ma iis : R 1kQ 2. When J, is minimum, J is maximum and vice versa Thoreisre, pee eeraec ta 4010-32 10ST, Tena = 3A Y, __10 once, as = 125k0 Be bean Ros Tinie 810-* and P= Luin lina 4 let Jamin = 8 Therefore, IE=40mA~5 mA = 95 mA aes Yo = 285.720 Risin” To” 35 mA 5. Hence, the range of, is between 8 mA and 85 mA while range of R,} between 285.72 0 and 1,25 ko. | 6. Maximum wattage of zener diode is, P, Topas Ve S2'mA & 10 = 320 x10 = 0.32 W Que 1.25. | Determine the range of V; for the Fig. 1.25.1, that wil ‘maintain the zener diode in “ON” state. Figs 125.1) j Given: Ry =220.0, V, a eT eR z To Find :Range of V, Bere eins Ve | 4 1-845 Gem-1 &2) } fe have Yo ee fn ae leorma 2 BerBa, (220120 Ri, T2090) *20 = 23670 3. Lun + I, =60 + 16.67 =76.67 mA 4 [Be V, 1657 x 10-3 2204 20 Hence, the range of V, lies between 23.67 V and 26.87 V ‘Que 1.26] For the network of Fig.1.26.1, determine the range ofV, that will maintain V,, at 8 V and rot exce ed the maximum power rating of the zener diode, wig: 10a [ARTU 2015-16 Sem:0, Marks 05] =a] ‘The procedure is same as Q. 1.25, Page 1-884, Unit-l ‘Ans. Range is 10.98 V to 15.08 V. Que 1.27,] Describe with the help of circuit diagram working of [ARTU BOIS-16(Sem-D, Marks 05] oR Explain with suitable circuit that how diode acts as a voltage multiplier ? voltage tripler. oR Draw and discuss voltage tripler eireuit, [ARTU 2016-17(Sem-D, Marks 05] ‘Answer 1. Fig. 1.27.1 shows a cireuit of general mulliplier fe, this circuit an bo used as a doubler, tripler and quadraplor.2 Gircut-Lisa Doubler (2) iret tie a Teper @V,) ‘iret Be a Quadeupler Y)- 8. During positive half eee, the dod Py 2 ON an 4. Inthe fist ngative hale Bee Vee Vey 2a) ia Ta the sorond postive te diode Dy E wtb cng 0 V, andthe capacitor C, willbe changed to Voge V+ (Vex) Vous Vn Yn? en Vz a1, Walfge aioe) Circuit 2! ge 27 Getler agra or nui {6 Daring nnd negative alee, he dade D, and de D, are ON, ‘volageacrsscapaors gens Vern es Win) + Vogt Voy= Vn WV + Vg + Vers 2M, a Now Voltage sro C,-> Vo Voltage arass Cy Vos Voltage across Cy» Veg = V5 Voltage serose C,-» Voy =2¥q & Voltage doubler: Taking ovrput cross, Vor Vou 2g 8, Voltage triptor: Taking ouput aereasC, and Cy, anges eapactorG the diode D, is ON and it charges Cy thie eel the charge on eapacitarC] and Dare ON, the capes 4 1.964 om-1 4.9) Sea eines 38, Voltage qudrupe ingot nna, : Vor Ven Veueivn Bhat QHETBE] What is volinge multiplier fs Explain the operation ef wllagn deen, i pm junction diode? ‘OR Explain full wave voling doubler with clear diagram, [RRO aire TA) ieaeeei 11 The circuit which produces greter DC atpt vot voltage using rctfercreut ncledanvlage malpiee ‘Tre output of voltage doable tw the peak nput vlagy ‘Thar are two types of wltage dubs celts Halt wave voltage doubler: ‘Thectretdgra snr inF 1.283, 2 ring posal fhe input og ide, feward bed (ON) and dade Dy nveverubased OF Capactor, dares the aka of secddary voltage with lay. 8 During negative halcyle, dide D iON while ode D, ie OFF. Gaya Ens changed ot altage ey the um of pedals ‘voltage and the voltage across C, 4, Dung positive alee: Vo. Va ete 5 Daring negative halle:j | | Wg Vat Vere? aM” YR BGT Vo mee Full wave voltage doubler St Tecra aiagram schownin Fig L284. 2 Beas cD, ON aD OFF. Captor Cy wil Charged toapeakvale Ve | cn Vou=V ising negative lll, , ie OFF and Dis ON. Capacitor Ci ‘angele pe value, Thus output veltage with nolo connected QueTaOI] What is LED ? Give iteprines a and applications, Principle of working, constructio® Semiconductor Diode [AL LBD : LED i spell typeof semiconductor pn junction that under irrdinsemisexternal radiations in travse vlad are Fopsons af letromagetie specu. 1m. Construction of LED: 1 LED is jst nat an ordinary pon junction dod where sian wed. Tere we use compound having sement ike gallium, arsenic and esha which re esitranzparent wk silicon which is pate {mall somicondotor pn junctions, meets energy wile givnoTas Feat and ome nto form of pats “4. Inthe materialeve slim arson pepe GaP) or gaia raeeedige (GaP) the number of photons ef ight ners emited is Bipntont to ees velelight sure, Recombigation g ah! OF Syabal C. Principle of LED: 1 Th precas iavoles: era resem of letren-ale pair EHP) ty excitation of sexinnductor. Recombination of BP. 4, Extention of photon rom the semicondcter. 2. Thecharacteritc for LED isgiven in Pg 2.292,4 | 1-995 emia j Working: } onion th on oa nt cee depuis en ecnbines hole inthep- pe materi When ent tke peterson lcs Fle Thor nthe frm ot hea ight Thetis doen upon peo materal ie, | Gane» ineed fae vai) GeP-sradorgrvn ih i) GaAs? ed orgeliotih | Aoplcations: | j Emerging Domain in Electronics Engineering er ore Djgplay LED ke caleuator digital lake te Ligh source in optical Bre communication Light souree in e source detector package like smoke detectors, ‘achometers, proximity detectors ce ] ‘GEETBOT] what io photodiode? What are its dtferent types 1 Describe the construction of photodiode with its operation. Rae] A. Photodades: 1 Two terminal devices designed t espand te photon absorption ara called photodiode 2 Photodiode na semicondactr ps junstion device whase operation i limite to reverb ean, ‘The typeof photodiode ae pedi péndode J ‘Avalanche diode ‘Te eatpucurent ofa ro ‘sexgostdtoiltemiation, ‘The variation in the output current ‘ha The construction an omen eae has -njunetion changes when devil 40 Soma x 2 Semicondactr Diode & Tie did is designed in auch manner thatthe rps are once a ejunton The remaining der ave rested Inning = aaa intent Boras 1 The Fig-1.20.2showstho V1 characteritios op junetionphatodinds vith ferent ilumination lve, 22 When no light ray incident, the doe has asl revere cure, own ne dark current 10a) 3. The dark current is that currant which exists only with no aplied ‘lamination. 4. The ncroat in reverse voltage doe ot increase the reverse current ‘gniiantlybeeaue all avilable charge carirs have lead being ‘wep aroe the junction, 5. The photodiode can also bo used a a variable resistor costralled by Tight intensity 5. Photodiode operates ia quadrats. in third qusdran, both and are ogative and power song delivered tthe dvi frm exer sireuit 1. Infourth quadrant, Vis positive and is negative and powers delivered ‘om the junction to theentenal crete aplcatson arvally tie ‘quadrant operations preferred.‘Answer Type and Mediuim Answer’ [sommes warner woitaia GeLAT] Explain input and output characteristics of varact lode, (AIC BOUTS Sem, Mrarsyg roms 1. Thi sale called a vricap, VVC (voltage variable capactane tuning diode, 2, Thisitconstrurted from semiconductor materials. Itis simply avo ‘dependent variable capactor, slo. le ol: joal- — ‘ ke =) rercy ofearair diodes, it > larger, then W = wider VS male, then > narrower 4. The depletion region Win this ease ask a insulator prevent ‘auction between then az proon of the dad, just hea dil ‘hich separates the two plate of capacior then capacitance, Cm «4 where c= Permittivt ofthe semiconductor materials, 8 Fig 1a. ee eee al «inet Fae fects ha ota 1 | | 1-425 Sem &2) Sereondactar Dade ‘Varicap characteristics 1. Pig 1323.ebow thn ratio typeal commer evaisle 2 Woe that therein harp ds in Cy wth ieee in The normal rango of for varactor dads tinted to abo 20¥, “4 Intormaot the apliod revere bin, the transition apacane a given spproiatol by 2 or TeV r= Constant determin by the semizondadr materi cd ‘onsrotion technique pee potential Magaldeof tho applied reverseia potential 17a rally juston = for diffe junton can Teer Fig-1s18 emf he capcitanee lhe er aaenation CO the capaance ‘funtion of Vy ie gen by 2 0 Coe Tayi awTSE] Replain working and characteristics of Tunnel diode with the help of neat diagram, [ART S015: 16(SeR, Marks 05) oR orkng of tunnel ode, Also sketch Diseuss the construction and w HeLV characteristics and explain. ARFO BOTT eRe, as OF] oR Explain principle of operation and. raw its VA charaterist construction of tunnel diode.3. The thin barrier across 4 ecrpaminmpwencitagineing PATEL Gy om eo ain th vt charter et ARTO BO1GTT Sem, Maa ~ | ronhintenne dace, TOTS a [A Princpleof Operation of tunnel Diode Intorrardbinesondion [bal forward pli aerate junction. seer etc ofthe pa der ths oni higher thane ae de By wll move blo Epos shownin Fig 152 1) el the eecconin Tn conduction had on the nid faces emp 1 2 ig 32, the junction would permit tunneling of electra from mae to pate, Pie tonside Tas 7 Increased, more suck wae ih ernest forward specitic condition would scape mien the maximum numberof filed states rahe eonduco ‘the valens ana Ul fae the maximum numberof empty statesi# = on the p-side. The ‘tunneling current would reat! 4d the consequent current flowing from tht is positive for this ease. As the forward bias | led tates on the n-sde would come oppositat® peak. 1-44 (om-1&2) Semiconductor Diode farther, then the conduction band of mee and ofthe side and there orresponlng tothe led states increased sida would move away fom th ‘woulda no ompty statnonthe pie Hence, tunneling current would goto zero and the norma diffasion ‘component of current would dominate, This result i apeoal or Junction diode characteristics. In reverse bias condition: ‘When negative voltage is applied tothe p-se wth respect tomato this ‘would push B, above Ey, with their separation being eal tte applied voltage” ‘The filled states ofthe pside are directly opposite tothe empty stteson the naide across avery narrow barrier ‘Thus, the electrons from p-side woul easily tunnel through this thin barvir by the process ofuantam mechanical tunneling and eppear on the mae, Since, electrons travel from pside to ‘current is from topside and i nogativ. ‘As the amount of reverse bias is increased, more numberof filed states inthe valence band othe paide would appear opposite tothe number of ‘empty states inthe condvetionband ofthe msde andthe reverse current ‘would keop on increasing with reverse voltage. Characteristies : Due to heavy doping, the current in negative roistance region is suddenly increased with a small applied voltage Due to this reducod depletion rogion the udden increase in curreat at mall applied voltage) i called “carrier punching through effet. the actual direction of Superinpovd semiconductor diecast Ye145.5 (Sem-1&y cern ciple of operation of LCD- ‘Que 133. | Iain prine i Tt [Aner DOT T Somme MAP Oy) viet Lc) ar wsedin similar application Whe De raring Slee. a Muanenest tom: S Dhsenictone” | 2 Dam rain eternity elie song = a Liquid ‘Transparent j a: crystal electrodes: Glas Mira sutface in refetive type ell gust Theil materi ayn nf sever ogame Bisham tsclonctr an in Liga tis aeretatren seth ith repre seo Stal onthe es fr. Wena api srs, hangars ing te {Eerie melclr alignment and reduce renee ‘Wheatbelt activated ts traneperent. ‘L_When dhe iu isactivate the lecular turbulence case ight tok ‘eitered i all rections andthe ell ppeare a be bright. ‘ements called djpamic attring i ‘b. Field effect type: 1 4 Monstruo field et gid erptl dapat {Oe dmanitatteringyp withthe ection hat tw in pla ot ters are place aie niet each gas shee. | 4 Metgudaytal material inthe feet clan diferent of ‘rom that emplyednthe yma eateig cel HL Themaeria ed is twisted eat i ; ctype ad actuals th sgh tl wien hata tng j Tis allows the light pase th y as clews he Hight to passthrough the optical ites and spear dl 4. Liquid erystl cols are of tot ten tu Tranamittive type: 1 Intheleansmtiv typo cal, th hs hectare mm A Fea OUI calteed nthe rend een bb Reteetive ype Bessie type cl he a eg sro side yan 4 Minn in hon utes a snl eee Bath yes fea rer quite hight when acta vnende aie 4 The aid expt ight rfc o asters hire hey costume small amounts of ergy ene les soe * Siatratnnsicnciegernentacetee age et 8 alk 1D whieh cn wo on Cte LED ei A ge 1 Auplevatog spy todas LCD 0 pak pak ‘VERY IMPORTANT QUESTIONS Following questions are very important. These questions ‘may be asked in jour SESSIONALS as wellas | UNIVERSITY EXAMINATION. [Explain the VI characteristic of pon junetion diode. Draw ‘well labelled characteristic Rofer@.1.2. aL ofp-n junction diode. How it 2, Beplain the Ve charactors is differ from zener diode? RoforQ. 14 Explain the working of half wave and full wave bridge rectifier. Refer 1.10. Qs.1473 Gomi g, si Fora al wave eto devive 88 PSION py ane er 13 i {8. Difresns between hl wave and fall wave rection, She Remra. 32 6, Stteh for a0, Fig. Awe Refer. 117 47. Describe with the help of circuit dingram working of voltg ‘riper. ‘awe Refer. 1.2 ns BN to 8, Whatisvottage multiplier using» junction diode? Expl the operation of voltage daublers, ‘am Refer Q. 128 9. Explain input and outpat characteristic of varactor diod: Ans efor. 131 2.10. Explain the Vi charactoviatin af haat‘Bmorging Domi in Eltronie En a Batter: {Thies the let hand section of he raise, ‘The man funtion ofthis region te —— (either hole or elcron) to the hss oe yo ‘oped in comparison tothe repens coe be Base: {Theme section of the transistor ishnown sas Ths is very lihtty doped and i very thin 10-*m) a compared to cither emitter or caller so at I say pase mont a eee ‘Shange caries tothe calle ee 5 28sgem162, e. Cotlecto {The riht hand stn tents kwvnaetit. ra) 4 Themain faction ofthe alrite cle mae ear carn eyes trasitorieathreeayrsomizondatr device, sandnid| Tough ane rode Le ee ee cue Coleone iawgh 12. | ceocoretneetceseecermte eee oa itowiayncasotrnitsombatetenitershisienesinp {strom emitter to base 2. There ar two types of transistors: 19 In most ofthe ease the collectar opone made lrg do ohn at So spstemiir aed that eollctorbas to dissipate much greater power bpp tcaniter. 10, ‘Thojunetion between emitor and base may be called aremitter se 3, Whenalayer of p-type material is sandwiched between two layers!” junction and junction between base sad solletor ny be alld at hiype metorial the transistor fs known ae npn as shown lt collector-base junction. ig 2a 11, The emittor-base junction ie ways forward biased while the 4. Similar, when layer of-type materiale sandwiched between tet elletar-basejanetion isreverted biased, layers ofp-4ypomateral,thetransistorisknown aspptransstora! 42. ‘The resistance of enitter-base junction is very eal x compare 9 shown in Fig 21108. (llectorsasejanton, [5 Thotransstorsaremade cither from silicon or germanium crystal. 12, So, frward bias applied to emitterbas ooetin is perl vy & Theaymbols or npn and pnp transistors ae also shown in Fig. 2.1, __sall and revere bias oncllearbas junction such hither ae a " 2 Qa] Describe the operation pnp transistor: ‘ewer 5 se orward bias and elector 1 pnp transistor with omitter base junction as forma (@)Structreefnpn transistor fe sedis own in Fig 2.2. ‘so junction ab rversed biased a eae are tive terminal of sue FT ® | Teleotpexon aerate brs 4. Topi rer a enter bse jtiano 8 Base ‘iesiacear ()Streture opp transistor Hie snd is coe Sea Soe me 4 Thovidhoftaois very thin andeny 5% fines nce 1 Ateantr hatte doped repon Fes thet gen ccna twtr —_———T:wrt | | pasieemtaD | eae nse ant onter into | sare be to drift nroce the a «See Se et ce xxiv coecor vege Ver TR comely oe | eetece bes leer Tesla | niterjuntion | Calter jonetion [Asbole reach th allectr, letron ere omitted from the negative ‘Seminal of battery end neutralize these holes } |& Now covalent bood near the emitter elocrode breaks dow The Tiered electon enters the postive terminal of battery Vag. Tis pretreated agin and again. i 1 Asthe width ofthe bass rogon every small the ratio oboe current fo clstoo current ie very large so tho slctron current may te pegleced 10, Toatonly tebe cuent plas the important rolein the operation ap ansitor. | GRETA] eeplain the operation of npn transistor. | on Explain various current components fn npn transistor with help’ ultable dlogram. ART ROT Trea Dy Mack 0) 1. Thebinsng of npn transistor i shown in Fig, 21 2 The emitter base junction ls forward biased because electrons a” ‘pelo fom he negative terminal ofbaltary Vg towards the junio Mis olor ajo revered sede elatrons dt agenda wart uve cole ome Sister pdm aa oi |b Since the ptontialbarir at the ined base regione very thin a pase tne region ato eal donor ily dope ict 4 Afow eletrone combine withthe bt ‘ange carlo. es a peon andar ot 7 wilt eae ee Nepstar atte etter ramets Se the current conduction is mp tari crit by clectrons. bag rer 8. Applying Kirchhoftscurent aw, teeter le 10, The colletor current has two components the majrty and micaty Carvers The minority curren component eal leakage caest eo So) elena * Fine THeRAT | Deserve the biasing oF BIT rei ‘xnewer 1 Binsng is necessary toetabish the proper eon of operation or AC smpiento. 2 Thoemter ayers beni dpe bea ht doped ance moderately dope. it an bere ectses 4. "Thislow doping lave derenes the conduct “ Fae sae re materal by ting the uber fe" re