ELECTRONIc DEWICES Gt |a044 p ASSIGNMENT~ A>, oud | , Short “Answer Questions > + ie) wo optain expression of diode voltage ond calatate the diode valtoqe value for a silicon cicde qives ig Tor inh, T=2mA and Vez 2é6mvV. ' Me ee Aes Je To [ =| y ; yee | ae ey os DT yy ees. To To Toxieg to] bath sides : a WT Ss i oq e cl at foty igen re hs = Wis we) Ve qr do ae “| | Gwen: Ts eTo = bh : team Ve = 2600 i = In ve Yur = io at)= “pew AL V = ax a6ew. tn [Sent V = wisn ine evo at jo Vv BOY 14. TOV. Vo. 75pm (or) | orgy | | * (a) | Dikirguish bebore? dragon and diffuser | Capacitance yw PN Ferris, diode: i Ang-| TRansition capacitance + [AL When PN Tunctlon ts veverse Yiased He depletion xeon act &s an inswiak ov iss. a | fe ~ | ictectvte. medium ard ane PyPS oO NWR SYED | tase tows resistance and act as the potes J2 Tus this PNyuetkion can be centered AS a | ts | Perealtel pote cespacttor la, THs juction copacitance is called ac ayace chuge [copacitance ox tansition capacitance and denoted as CT. ard defired as | T= 38 fay, whee, de~ is inteate in chage avis the change oy tnexense sovotteg 7 __——“4 e-[4 when the Junction is forum , biased ,o Capacitance | comes into Poy Amt is Known oS diffusion Copactternce « deroted as cD. Te is much Greater than Lhe trargilion eopacitorée - & Dosing Forumd biased the potential, ewciey | is vwecluced. The choge comiers trove “J Fro | BT rw dened AS CD= 0 fv. whee Tis the mamlife time of the crate | the jection and vecambing / = | | | camer, TD is the diode current and vt ts the aglied forunrd oitoge, ard i tS Geneaton | vecorbiration factor @ The yeverse satunation cuent of a silicon | PN Turction diode is (SHA. Caldilate the diode | currant fir the fenced bias weg ° of a6V ok | ast. fas Given? pyae i vK (Pecans of is im | Goo AAerrppncntiuye =p corvert Yolo wy Wie p5te 2k {600 GOO Vi = oeoasy Gx) a6 7 I tel ewe eT| , 6 [Sees Te 5x [= A ol ‘ Te ae a t\ . 2 : 4 Te ext |e -\\ T= up [epa5t.6 17} : Or fE2ISG Te \H¥xoLoTTHY TH aUEA (or) BOA:Se C29) Drawn energit’ toned Aiogpeet of inbinsic serticemdudley | and define drift cuvent. fos) Treg Veen Sioa of tabansic i gericandutor je 4 | } Cocdurlion aan | to | . ; | vk! . t ces | LG, | ty 7 \ == il a / | valonce bard i ’ je, due to Mav of carriers Re “ny i ied‘ Cretes] elections) oth in region due to opti vottoge The creo} comers duift Born one § point 10 another point en Sousa divectian dont curvant prft “euwent Tt brat gives vise, to -Tt 6 due, to met carriers of the region Eipp © Tan} |(BY) pistequs Disliguich between depletion and, dius OH —_ Afacitence of — N Jumetion dicde Temsitton fepletion . cagaetlenes « AL When Peni Junction AS weverse biased the’ depletion, vegion, ak as of nsuleler or aq wredium, ard the, P-type an Ne te | dietectric fe and act oS the plates | Tove law yesistane’ | can be considered] as Jasktmas: iS pr Junction he povalle| pote capac [3 “THs ganckoo capaciiarre ye called aS Space | change capacitance 0 syansbor copoctonce | | amd denoted as CT and. defined aS cx = d8/dv dg Ss increase inchnge where, av is the change in veltoge | | Diffusion capacitance t- Yre gunckion 1S Resor into plo, Brat 1S Keown ds o. This A. When 4 ised a | capacitance comes diffusion copocitonce denoted as C! | rensch greater than the tremsition copacilenee:2. daring, Abe Lemwenid iacech the pctential | ory is reduced. The chage cemiers move avi for the Jurction and recombine B Tt W denoted as CD = TIO fe y where V ie the mamlife time of the chaige canviet,"” qh 8 the diede cament, Vr is the applied Sounord willed. andl 1 8 gersrakion aqcoretivation| | | factor | (| Delire the static and pyran, rresigharce of Ye pn Junction diode- |. Stodic resistance ‘- ; defined as | adicde qe static resistance R & 4p the cumrent. Ey | | ene woo -V/T of (re voltage i ee Crennckeristics of the | | point on the Volk -arper | dade, the yesisterxe R'E egal t the i AN | ecipiocal of the dope of Ene jening sage oe y ie to khe. oAgin- ‘dines slat | here Ris character westtorce | als | . i | | | || pyremic se aesidance’) Te 1S delred as ne Aecimecal of tne slope of uhe Volt = arnpere, chmaclerickics, vedvids: “The dgrermic Yesistance, 11S met constant, yt depends upon the | cprvaing aanent 3 ve My | | ve Wr A Fa CA) Explain dritt and diffusion currents of a semi- conductors ‘im cetoil- ins) Dette Quryent > rt is due to Ftow’ of carvers Choles} etectrons) with in, wegion due to opted ( wattage +. when votkege ts aggliel » aegis camMers | ditt Som one paint tO axntkher pt in forward | direction tra gives wice to drift eurrvent - ia te due to rdjoril caries of We veo: 1) {Em © Ts) - aDiffasen Cement! 7 (Athen lasersi comuttor iis dopped | covier concentration Vanies and the Kree aarriers . fav from one raion to other ~eqion and this gives vise to AiCfuson cunent : - Tre camiers crossing genetion Chole to. erect) : | teccemnes roinowly comier in other Tegion + so ot | | diffusion curent ts maint quvvent of «the region “Prpn cor) sag} o 0 : ; ©, Uihot is reverse = Tee time ofadiade - oe Reverse rian ree Cer) Tt ws te me" | token by the dicdé to settle into wan stale | when the blas is chang ed Brom forward to reverse |bias- Tn this Lime ig coraidanbelly High. | ° ‘ (a), Distinguish between, Zener breaucdoveyy ond Avalanche | preaecdoen 0 | Junction - chants Wn yeverse biased PN- antl pou a tl a Avalanche beeapdmon Zener break ous | [|The brexkdeon atchecnad “he zener breakdamn occurs || becouse of the calllsion | hen the ree’ eleckiific, of the eleckhonsinside | Pitch is appticd acrOcs |}ehe en = gonetion is | called — avatanche a pete loyvexkdowr | | |——__—————. pe zene knea¥dann ww thin region | © malomche bretedowd | Th ‘ s leceans in the dhicke rio" cece Aker the zeney breatdouy| Ane qunekion ‘epoine Us } He | patter the ayalanche | hreavdasm the tynctisnof the Aicde est retregat® eriginad position [its cxginal gestion im | he ayatarthe tsecudose| “The zener trveaxdeu7) eceuys in tod pong erty high depping rratertad Tes woltoqe is irverSete preprtiona| to) the bempactstve HS votlege ts dined proportional to the | eapeotene 00) Re valoge acme the Sidiode ts ot ah eo bik ae ate vote and om current” rows. Herougl pane rmeases «4D TEV = cokwoate “he AS Given | 2] Veo y | | ok = 30K | | T= wrk’ : | then ve oe) Gives) Ber}Vi = Reo \\Go0 A - = H Te re[e mm - 1 \ v “ Ss | e . a * Leo, Rl § 3) & a. taut 2107 aa oBlU KIO Ts = 1 (tomo \rfi Tp = woCo2>mA Tre od MM ©) loaxte™>A oveanb TOV (xD aorty’ |—Ansuvey Questions - a, ww | ca! Distinguish between chit and diffiisiod current in | ss | Semi cerluctors 9 D anede cathode Any a ——| jo LDMHE cument TL is due to Frew of carriers Crotes/ eteckwone) esth tm the region due 49 capil | votkage — la\hen, vatoge is apstied cogently eaters dif Gem one paint to varother point in Avast d, diveckion thot ges wise fo deft current - Drikt caveat is due to erase cavsias of the region Liye cos) Fn} a Diffusion currents When a geriicorducts \s doped carntey concentration varies. and We hee camieys Pow fin one regor to athes PGi9 ard thls gives 1 vise to. diffusion quent: be = _SSFTE camiere qossien jumelion role le election) become Mirmentty eavrierS iy other eBiO) » So diffusion Facrent IS reimonity coment of the region: | Prpntsang} CB] Dave the eagression for conlack palenttal Vp Oa PRL gurction® HL Grid a qreded PN Jinelton and Wes cak to | | voltage Vo Gr) Vy ave carne | NANO ' / { | | | | chevge concentration io PN: Sandon is | | Np — borer concent yoko | | The vet current density io the ‘wegion, te Sur of deft currvent, density acd diffusion res G | cunentt clensit{ . a i=a | v0 the wep bet the deta coment dent | Issuer of daidt ceevert density and 4ilusion: eament cenit ; Now otal cument densify i F*afien is Jp. 1 Eppe — por st, } Since the cerrrerk is open chevited then ae current density] 16 geo (3=0) ‘ o= 4 Epp p—gor go e Pe oe | BR ak E = tap Pode Sut e- -& ak -av = I dp Pe atsstepting on bath sides: Gave Pre a Pro v= Tp f Apap Ppo eno ve - Tele Ve —TpCy Pro le i) ve "eRe % do be Rp = mh 3 Nefig = me e ne Ne = ND ta = Tpln( taLion locke ay re Explain the emi of PN Jumctio Moy move circuit rforward and nevase bias ewith atiagnarns hw . ceanetion Ciode!: TS) Feward bias gf (junction, diode: —_— — i ‘| L_ “Nyt nN AVE Vv | Working of of Rogar. bios - then opptied found, vate ley Veo 9 otha \N the condition of PN functor - Hehe Se argy Flows Cie 3) | | AS Vineweases, width of depletion region idecreaseS and « negli egabte axment Plows | WIRD Vevy , depletion ‘raion 1s itera HAs V is increased beyond Vy the migpily carriers holes lune fron PSide Lo m-Sides | SiweMlerrld electrons eas bevy ‘aside to pide | ond he i NEE cURRENE lone across the jedon (SO turrent \Weveages. sae ead etiytyl, | So therebre PN guncton, diode Comucks @ Under | | | -fewsord bias condition,egptive of the Frathent, te covtnertcd tO), pride | Surat nly postive to nvside hele | Saye of the bathe applied to ‘pside a) iers holesare oltvacked eats caries elects axe vepeltcd + | with | Hits reaion ty cart | ‘ | and 4ne minor | toward the junction ‘shelley ak omeside the wrinorit comviers Holes ave’ “repelled tourrvde re er ; ith of depletion region Levthey usd cannenk Hows ‘mcrae and hence TO fo (iso) bot thee 15 a nghegable reverse current: (D| Epon dicde snitch, chorackeristics with une forns- Aye Diode gsstehing charackerithee lewhen the dice 1S qererse biased thae a wide depiction vein ok aueion ond current iS ze). $0 diode ie of f- —-As a negult tre ot | | L| — ‘ \ furl bias is aplicd the a [eateeo, the depletion veqion quit dicappenes and clinde d d . 7 celle into new Slate in neglgeble time te, tm it is found recov time CU) af diode ~ Fewsrnd ‘Yecovent tame Copy) TE §S the Lime | taren ta) the iede to. eatile who mew Stade, | echan the bias 6 chetngé Fron revewse fo -fowred | Hence ime is. magia: — Reter iy Hore Mer TE is the 4 Se yecovey ne Corr) <8 tata | Py Be dite to gebtle into new stste uhenthe | bias is charged tim Roucrred tO veyerte bias Jy this Bme is conddaatodly high. , Description '- lainen the dicde eas Pesucard bids the eexjppeity into camieS beleS of paregion ore dittused Siecilany andor caries ekeckeens won are diffused to p-rVEod: now lias te applied this dttused covsiers ave invert back ky ‘there seegpecve onl Adode jaith settle, Wwiko en ‘ ss ty ty S Ais, pipcess, Love we. OD ie jneregion 5 | of veg 1 vonen - yevewse | eA then | Stake cnc | axe: ¥ |} vg) piade ' ~ eM or ky TMP | voltoge 1S Cave VELA ‘is fond biag , a Curent Tr Vet /RL. ‘Hows and Une canniey density 18 high: and the diode. ; voltage se cde in, voltage Vee Ae tab, inpul voltage chang ec to -VR so due to the reverse valtaqe athe rly camiers diffuse frorm one region to other ‘cago one xevered back go charge densityfa dearases, ab tet bh becomes zero Nexo cteptetion region 15 start oven Bak ab Lety ceement camtt Pee soy IC: ine ctiately anti the diffaded chonge Q, ce © Yevencd pace, 60 aS negotve camenk Fo 4 Se, VR IE fom Lito to. AE L since changes ame reverted current skavt eheoreessing nd goes ke everse galstotivn Comet Cis) ak teks - Now the diate tg Setited No maw date - = Plode —yottoge Form ti to ta Wie checrences then ty totg YE gees to Sve and at ket, 1G Sve: signal 1S applied bo tet, te dhonge the cordition of diode erica Ye tS gebtted Ino nanstate trts- So the Lint Ly, te tate reverse Selo sre Ui get 1 W ceyy= Estbe called & tots ic calted ag Storoge kine ~ Sloraje dime Is a Lime taken 4 the diffused carniess Crrinovit] carvierg) to. boetome 70 after the application of yeverse bras te =bransion Hine Chi ts) and te is teeen hl the inde to Sette conspletsty ‘nto a ed gdb Pe—————_— zene diode canbe used as vyortoge vrequlater «Tastefy it when tre Zenéy diode is given yeversebiar feedback, there (a small tenkage cement until 7: attains the, Frcaledaey yotloge oy a contlant velloge . AL EIS point, the current begins fowng geamlescl{ | asanout: amg change iE in vag 2. Therefore, the. corttant — vol belps: Zerey dicde as ier 4 Carrer} - wlokoy- Nettone 73 E 4 - govt fe TRY gener diode is Specially designed fax this vetkoge | veqilasso- The Sex conducting sion crateria) US in the zener dicJe as volloge vregalokor: (b)) Explein Fouard and veverse crnadertsies of | | py -Tunction diede - Fouad. bios chonackedstics ‘i = when applied cfirascrd vestoge_| I i 1.6, Veo ne change in the Jcondition of ER Turckion Bene no cuvert Huse Geo) | AS Virevases, widthot ‘tps alepletion region decreases ardq Vv Neglieqabte corveent FlowsWhen Ve Vy, depiction vg? is vanished ~ AE V is inneaced beyonel wy the ‘ecjenty |, emias tples flows fren pside to MSide Siniknly elecbrons flaw ftom side te Pde, os across the Gurckion., 8 | ard hoe — camenk flew watt, vvh jCument — increages exponentials |-So therefne: PN - Juretion’ diede conducts under — fravaid blas condition), ea Choracteristies of Fonad bias | — | | | | ali ° Ww Sy prelion of Flas of poles 1S Woken ak, weeheencel eunsent direction - Reverse biay'- Chrarteristtes =jo Negative of the hatte is contrctecl to pside sirilily positive to n-side hae | ' = with “vel of the battery caglied Ae pestdelragion) ts mapitty eames boles me attacted vt side and the minor camiers electwns ave xepeled ctawonds the junction. similarly ok w-side Lhe ' rmivosily cariers holes ane sepelied ousted’ the gusction HAS a nesull the usdth of depletion ~vegion inthe yorensee and hente. ne fwsard carmen Hows Cres)’ but thee ts a neg liegobie severse atten | Ver characlerttis of reverse bas! t* isn pes To is a maximum coment Mow undey veverse bias Condition } Ie reverse sqiunation comet yorder of reese current ig triad ampere Cios)and iw sofilli armpe Cte) .a > = 2 TP - LZ ze =} Obtain the expression er diffusion Capacitance iy oO fiom gpededl gpeetion Diffusion angacitamnee tater) Ene junction is ‘forse 4. biased a capacitance corres Whe m4 pirat ts ij Keen as diffusion capaalane And UIs denoted as oy , When a. Prd Gurction is faxmard biased eraforty ‘4 COMES — diffused from one-region © olhex veyon These camiers ore accumulated ear the dw ete i [Br a0 opplicd foamed bias vatkope V- 4 | derivakion’- i Vi | Copacitance is defined o& ce NH. diffusion copodiance 1S defined as Co = de [i arte vorto caput | ay oe) | | Co= Tt > ow yy t { cos qb “ae TE |ene TH yt wy) Zen diede is ased to supply an opal vertage of | Jav- The & oll | “ey ele e 1S IBV The zener SAV jand requiyes 4 senimirersry dod. | calculate the Series weSistance and the yong? Ney uahich he toad resistarre RL can te varied - In e arent of AMA. “ T ah a RY je ‘ a wt & = vo ; ; Lp a No = 1av Vy ciaV Ve lav Zzimin = toh Rie- R= Rimage G2 Bimin Ti dz 43, — 30)a Riz Vos A Ry = ta a Pet Tmax 1S era and Tpreaye abe Tis Agenint Feo Te yaemar Tis QomA Ra. Vi-vz ry F 3 Rie 2 bode £28 arog 20mA 20 4 Now", Ti = Taran Tien Bom = ramA Type Tyxrin= Qo -amMA Lyme enh Vo = TRL , Ree aL Risin Ne > Ww Tyxeot YeeRisen «88 se Bix 1 XO 2 KO te PS hase Now, 7 Qrox = No edb we Treo “GA = Sep | | = (00. e { : alg SDe o> _ Tre worg® of R, varies from [osenbe 2250 ? =)! i Giode . tow! on diede. & Whot iS a breakdow? cpeting in reakdown seqion be used fbr | equuotion. 5 in heavily dopped PN Jurckion diodes erdey veverse bias condi bo { texge nureber of hh canrentt Ny Breaded ccaxr’ | Breakdesn exes Brentdon oars due generation ol free electsonS ard toles . A anesult ahigy Lows under wevesse bias condition - eowdoan TiO can be labors , W) Zeney ; Diede cperaking Ww used for ~qqulation Cox) ¥4 break dows conditions -Ne Zen break dawn’ — ere “fice CHIEY Neg Lare — 7 “enegy How aptied ptentiol to Fecal along, Que to the high severse Bias there 18 wide Aeptetion Negron ai junttion aM $9 eledaic fig ak the junction is strong Cezvart), DUE 4 thy Story Aecliic Rdd ot gontiod eed Perch , trea and fee eleckon- rele Palvs ave | s due li ae Bee elect vn al P high current fan under reverse Hac ard diode i | said to bein byeakdenn , tis i called ag | ener breagdonn amd the diode re zeney diode. | Due to abs gpecifiatly ofeation EAS used ag’ | voltoye requicter Gy) xegaiation: | Cheult “of zener - veltoge vapor * i- Dracbays rev b osbaits of Zorn. vee nee ' - 1s efficiency ie lees Ae teavy lood cunerks = quip’ Valaje Varies usth zener diodes unpederee ord coment , 6 Fup) 206M ARE ciffererce between zener brent dus . ard avolancne breakdasn in dike} . poe Avalanche brenkdoon > i —— (Tre breakdown which occurs: because of the colliSion ok the elécbrorg nsde the PN jurction ig called avalanche * treaikdosst) lethe avolanche brendan ecturs the apick veo” pp. Kies Yee ovalanthe ‘ereakdusn, tre juvcion Aide uit ree wegen ks oxiginas position - A The ovolenche Irreakedonn produces Ace pairs of Jeesone ond holes because of krerrnas effects | «teterals | 6. Tre avalanche breakdown yoleage | causes becouse & high reverse gtertial becoure WE Us tightly doped The tesnperoture coetfictent of the avalanche | | reaydauoy 1S positive a of the! | le.The oyolonche ‘ereatdeng cccurs in tor applyi IS TM avalanche prea dou) he enechani srt ft af callision of electrons Yonisattan ofc urs pecarse yreok dow? vatage ss ‘ whe pereperature direct roperdioral to ae e oledtxte Herd ks leg. 9. The avalanche we. The existerce of on the axalanche preaedoP0 zener Breakdown + jpn ea dor \ TRE zenev ar eats waned. tne. heay eg the Ne guetkory “if electxtc field 1S apgied act! jg. THE cere eo do00 ocirs OF thin ~ yrentdono the junio part’ . lo The ene dhode Pouce the eleckWs , renin Bans wo tigh desir a. fetter the apenet yegauns ‘WES oxighnal | §. The zeney | rrateria) 6 . Whe zener oreakedous) ie pecayce of (ek ea potential : ' + “Tre | ternperodnre cebffictert ot genes bret je down » ie ve | ‘ [@-.29 the zmer reokdann —ienisokion cet | because of dade fteld ”_—_____ A “he zener Ineardown voilage IS veers | | gropentiona) to the tempevaltve I jo. THe existeate of the hectic’ eld ic gare oy Lhe zene (seat dowry ia] Bxplat the orrrntion of gatential teortey acwss & MM junction cede with wep blas, cerdien Discuss the variakon tm width of “Ahis bavier ott are optited weltaqe wr Resa Bad tecrS biased conditions. #87 Formadfoo of depletion vege To ‘enbansic geeni-corductor charge contentbalion, uns uniform Arnagpoot athe tenth varies eapsnertial change concentsokio este dof! " conductay WHE Is colledas oe we length of sek | dersity groaient . | - pye to density gradient tree 1S OH ‘ (aiffaence of ey) Length dee to tris poles forra PIGOD sreonbice S , extrange of ae] Bone pont 42 gotat aver tre | atfeene enegty the free | ll enter ante vegan and wth the deckoone there| i | i eee 10° G07. Seng fee eleclxors Go! anes est en the holes ba ocess. After — Simi larly into Perey Unis is. called are ond of 4 cembinaion POE region is formed ot ie Laretion, depletion “4 due te enrol le caress These cortiess OF lastly exossing hotes rire foo and gecenhit okion aecomhin cs adepletion } 6 -orrmect | Seomebi le pion avd agieuen wegen Po sta han'ie tH : fe caclitS 5 | a renedel — Valto4 < developed ocaurss te depletion elon | gue. 40 imrrobile corners *S called cot io | yoitage (yy) Cod bariey gotertion to depletion vegion ot gueckon chasges 3 tow Prom one Side + other side wet cornet Ftd tS 4210," ge — pe Cam as’ a yesste the under’ opesr ‘create candition Sot cument Fle? —_cewass'! the Guridion J PX per) muse be biased. 1 se“types of {sia ‘| 1. Fournd bias 9. Reverse Ibias Fawn’ bias an principle phe —wthen applied foruxrd mr Le, v=o, nochange i the condition of PN jjurtkon - Hence no cuneot | Fess Cizd) [nas Vy ineeaces width the depletion band a snegligate carrent Hows |e when veVy. depletion region is verrished| Lone VAS inceaced teeyond Vy the syomished | reajontly cansiers bles Pune fron p-side to vrside} | sunilarly electrons Paw for nrside 40 pade ‘and Hous Across! etne gunction, $0 agin decreases | hence cement | cunyenk ‘werenises extenentially usd Sul, a Lrerefyce PN function dicde canducks under bared bids condilirn «——— ———ee 7: jundliony i Fmoma py iy _—$—__—_— Vet chenactetidt ee at pr ‘ — J ——-> ° vv v gf pees FSO 98 vefevence pivection of Hew | | __ = } Negotive of theY hottent is conmeked to’ pastes] sitilaity positive ton-side here: |_withe Wve’ of‘ the battery applied “to 9-sde Ne spay ty carriers: holes are oitracked ceuksde and the mirtatty covers electung are xegeied ’ sowstsds he Qurdion. Gorlarly ok side NE | vrinoty Coxviers eles ave ted wisi ithe dunction.——— 2 AS a yeatt the width of depletion region aur ‘macases and herve no Pownmel covert flout D (120) BU tae As a netlicghle reverse canent} 0) Revase blas V=T chayacterittics = Aw “ ye To is a rmanimpra curgent, Man under eres bias | condition 7 r | order ot reverse anrent ts rien ange Go§ and cil“ omper® (0?) «| obtain the expression Lox Aiffustory ceaynditence Li a se? greed junction: | An Didtuslon capectaance ay saved A capadlaKe cones jako Py | Joan as diesen eacaicitionce ack | @) when a PN gonction is forum tased veqipily | ‘comers Aiffusedd tom one~ aeqion dp alher aegion | These comes one accumulated sean tre _nction fer oy aatted cant biat ast ve co's when he juection ts fouserd thot ts dereked aS ,cewation et ce W ‘ h copadtane | is delnd as diffuxien cogitaree a fas (De fa 2 vat ql