Table Of ContentDuality as a Guide in Transistor Circuit Design
By RL, WALLAGE, JR. and G. RAISBECK
{Meme sn Sit 26, 20%
we Se a arog ‘Bane rena eae ae
‘Sth tala The ature of sh butalormetion f Gsetted sod & eoeabet
Tea ae.
“Esmiepvenion
MINCE the investion ofthe transistor there hasbeen natural vendeney
‘te compare ils properties with these of a vacuum tube triode, This
Compavzen india hat the owe davies aze diferent in many important
respect, For example the grounded cathode vacuum tobe is essentially a
Sallage anptiving device with a hi inst npedanoe and « relatively
Toy oalout lnpudiaes, ve tho grinded have Uansitor i essndally a
‘nent caning deviee ith «ha yu impedance abd erelavely high
Sulpl getanee, Fathermore hig ya aguuna tubes tad toe tatcle
Sih upon cenit terminations, wile Bigh gain tears te om che
ter Mat le usable with shor cet termina
"he properties uf the two deviess anc fac, co radicly dierent shat
the developscest of the tragistor ws peel wey naw set af cut
thesigyproens f ke vactam tes twee te spy epee
by tremors (and appropriate enanges are made ia the supply volags),
itisnsvaly found that te turer te! bs et aeanage ad the
Creuil psonmatnse ie aoe sistatury. Fur this rao, cleat dsghers
hreviofoe have essed cnsiersble ingenuity in devising new ects
sth take inte scr! te pears of Che tnsisor and ure them
That edvantngs, Tt tars ot tat some of tics crete bear lie rsem-
Hace co vacuum tube circuits designe to perform the am nation.
‘Although there i gue difeence kenven the eecrcal properties of
stansior and vara tle Ute i a vey simple apororimate relation
thip between tet. Te the purpose of thi yper tonne How Le pss,
{aking ts lationship Sint account, to stil with x heen vacua abe
Great re tranfeen i neo compstely diene: sic saltable or wee
‘vith fansite, Civuts deriv inthis tel ake advantage nf the
Decilarties ofthe tragsetor amd amir of races have sown een
orally ee perfrmanee
yeaa, alway 1951
‘tus Retarion sumweas Voce Tear’ aso Tras
‘eis te purse of ts ecient how ehat the properties ofa trneitor
ny relat to thos of e vacuum tube tied through an intereaenge of
Curent and voltage, wl tha cence eorront ee ike sri rie
woltages and vice vere, The dzcusion is rel partisan ot te gee
‘gal poperse ofthe tro coviees ars i ever to the frequency range
in whith staie chariteitie ar auficent to determine eeit perfoone
‘Consider Sst the grid-athode‘npat terminals of a side ne compares
to the emitterbaee pot terminne of x tnmsitor, With rept to these
temintls eich device behaves like eter the properties of which
faze relatively united by bites appli to the thd elcid (plate ot
‘lec. The gi dacs when ied in the Feral ition od Sa
to contac whe sed in he verve drei A sila xan an
rate aul Uhe elie, Farensine, eur device beaves a loeb
lance wien btu fa the forwand diction ad a a celetiely igh i
elance when bie the rene dion,
"Toe diferesoebebrees the enti vu sa he ideal oats sb
in the falling way The vaciun calle i nt flective ae a amples
hen The wd eased inthe sense tection, wile the Wraps: ast
(Afectve wher: the miter ia Vgc inthe fran deton, With respec:
to thee inpce ermine, hes, the escent ciference between the to de-
vices emounts to tae erence besreen “orwand” nd severe Ht this,
4 tain, amounts tn an Fate senge of ements lag
‘Whatever qualictive slaereats can te mice abont emitter earent
snd voltage am alo be male abeut grid voltage and caret, espe ively,
or essrple, the gr ie normaly von x maerate voltage ine at hich
the gid current is esentally zor hile he eiler ix oneal ven =
saderte caren! bits at which he emiller vullage = eset rea
Torthermare, the peinepal nos linearity inthe gid cree accu when the
(gd voltage allowed to suing Gough sco wit the result chat gti eu
‘esl js Un se, whe the pinlpal nalbeariy inthe miter evait
‘nuts when the emicter cme ie alswed to aving tarough zero with the
rel iat eniter voltage begins to increas.
"The eampurson Hetwees the plascachede output cist of tae wie
san the oiletor base output ete of ta tesmsstor's somewhat compl
(als! by the elects of wis nd erate: biases. Cosi: dst the steation
i with un bias ie applied to the put ctcite Gy = U atd fe Di
1 this cee, both the plo ave te elector behave Hike dice rete,
dusting readily wher bined ia tke ferwacd dizetion and conducting
relively posiy whan biol in the soverse ostion. When inp Bisset
om Paoveaais
DUAEEY 46 cUMDE IN SHADE CRUUIE DISIER 388
an upped, however, tke psncpa!diference Between the to devices be
fone appar: ard arnt ohn ie wsuwated ith the dilerenee
Setncerforeand and severe, This ncn in apo t the gr ect
sey th format part ofthe pte cri crac wile bisses sped
{othe emitter aot only the reverse pet the clear cia arate.
‘Thy the rid and plate are rormaly ise in te reverse acd forwan
ivetions,reepect'vely, mith heros! as ne was tbe ap i
dance & high end the antpat imps eral ely Tow. The eter
te cllctor, aa the otker hand are normally based i Ue forwand st
fevers directions, repectivey, withthe result thatthe taustor iat
impacance lw and the optima relay ih
“The emparison of vacuum tbe and rast properties be card
further with the lp of Fig I() whieh shows te platecirntclarcceristics
sa particular euum tube erode nnd Tg 1b) which shows the eolesor
‘eeu earactenstics of particule tristor. The axes he no Gite
lave Been chosen to facia orparsn of enn catzeats with vacuum
tube voltages ard vice vena. Th nots Unt the two ics ok ute
scar, It see. that the qoutes be compared are
spot ie,
eth oa
sy wlth ab toa nat shown,
Sie wee
“The consetnt dfernce in sg lwo varus tobe gd tensive
‘quaniis Holds rly we the treo saad Fs an ae see
futon. H the trincistor ie ade of P-type mated thre isn diference
Insiga between sorresonding easter and wacwima tube quanti.
iy mlering to ig (s) ean Be sen that to mrs approximation the
tiect of applying & negative vltag bine to tho avi ie simply to ail the
Dale crit ehamctsiis to the right along the ty asi, The cumber of
‘els sift cane hy «change nf ane volt onthe gtd ie called the voltage
Brapliseston factor, uy of the todo. Similaly, 1 can be seen from Fig
(hal he racial fet of appvinga postive current ins to the enter
i. sly sll the soluetor etewt chticlestic te eget loa the
{cau Ta member 9f milters taney cage ia enter
cument of one miliempere'svalle’ he caret pliiorion Teta, 6,
ff the tomar,‘ Ue iar cuneate vacua,
tute
the pteenlam ages, WG ne and JIE Sea Pre FRE,
38h nam nea erotik tremucaL joumuat, are 1981
eis ntecesting 9 note thot the gis mainte in the acim tube
plate ctcit have tae onustensrte La se traitor cletor eet. or
fearpl, the exurenys of ple canreat extol lector slag cut.
"The latiorsip beeen wien tubss cad teaistors is aot ely queli-
tativ ut a bensade gaat tive a ell prove sitaleenec tube
ove for compar3>+ with rnsistat ‘The rogcnerents are te the
‘acuura tube and trarsitor hace siwlies dspaion ratings end thet w
bi equ toa. "These coins are caghly excised by the eam tube
fd trast of Fig, Tia snd ig, (2). iy comparing the anes i hese
ve guest may beeen thal ony illasipoge nthe tnnsstorcomespons
ek ke thf te
ethan Anse aT le ne
ig. The shi cheat
to 66 vols in de vacuum tbe and vce versa TZllows tba inthis ruse,
transistor unvnte ane tlatod to yuo he voltages through 5
Fm estan” given By
mcm Cosannnatioss
‘he internal struccane of a wacatrn tube knposes a particule set of
Iatonehipe between the sacauan tube carer's al potentials. At low fe-
‘quencies thee rte ave given by che slic characteristics wien
som ul ae a i wide range of wes he tube currents are rush
Ten fthns oC vals, Wher Ue Iris rane ie a ele
real, evi ingame a cord st of slg reliant
acuama ibe currents sal paallas ars the pestmance 9: tae cl 8
sean eptecentsa sivnanmous sluten of hese ts gee of rina
Now the vacua ipl msisterasé che exeral cuit
ig left unctnnged, then the rate nso impos axe Keds
Changed rhe she rlatiealips impose bythe ex ckviri se ell
Coles lal thie wad ta comely ene ane
{Druin far The bn sts 9 ceEesons ms sence In copetly erent
cir penance ith respect to he een he us ante
to.) to be mained ar subetitting « tanesne Sa © vacua tobe
ion te salen ciel must be medle Cm ght saps, fr eae
Sot isc het Ed 230m exsene Cnet sich al he le
Zor volte the ec wot eae ems ie the pate lage
into vpn cut, Te a cern eon hs ane, bl th pce
teste wa scious dealt Altay trator voltages ace Ly ell
eh, rss Sacer single values fonctions of Garsitoe ewes 5¥cr
(eile wide ssagee af tala Werslor vinn's ae slasvely tere net
Fron, olla double vested, fain nf ae voltae This mabe et ace
Ua if cert seam i to betaine fr large eal, aoclinear
fdementa ilo nod le rere) cucu Ths eppteach seems very
Sah ae promieng has ure bo wll we now come
{The new appro sin seeh 3 annaior “ie eke corey ren
bec cress vltage in new wri Ine a
(oor wolge thoes Eke a coceeponding mentees
ively imple because, fs wo oo ser al the penisole
Sine sachanging tsesor for wort ae, The vemlaing pat of
he dion i alan exter rai wish wi pee Cae anc ar
ins Hotrten eaessor venti val eves ay the aga! eu be
[ove ete vacuum tube rarer al pele tial This asounts 2 sy
Fn that i Uae socuae the Uae weaced by a device i whic the rales
si cunrnts wr yi ate jek Sotercbanged then Fe external gear
ould ¢a0 Fe rulaned ya ey ean waieh seer sve thie ere
‘eanctarge,
‘Notwurss ine Cs sat of inteeshinge & aosonptici ane ens
als. ove ofthe er T has heen born nthe Hera Fa pete
touind an tore sys ye dune ofeoe= practieal erie Ve total
omer of vino seuonte i a Ratwook i onlFurypomervel ht The
Chammnieee Negore A. io Wd 2624, ae ey Se
STR Gate vlna hes ia Jha
‘hrm es. stones reemead cours, ARs 1951
oa rasan penne, ei len beg tensor fat
ew elven hich sls dl, The tasted elseate are te, however,
conver lnger ine mane way 4 ene the aga ane. Pena i
pole’ re fraser eels rig a ie ema, Nn rr
Fer ate lens! ans int nes
“Teena rane sho dnd te ed of x akon, sage
seand aU reser mig ifer Ire the ala Conan ay ate
rien the network cnnaise mutual ingustance oe nonlinear element, of
{Ue vtverk cant eran on a a sunfce hous erceapves, Some
Df ese caene ane di hy Ra
Dusnaes
able 1 shams sie hy side a amber of network slements ond the dons
of eae element rele hn Ihe exe reste 7 The ae
tea shoo the das of few single rete, Tie tae pazpose of this
rertion to shine yy ries of eles how ter dal mitorshipe art
‘ant
‘hr nark cast the Gea another poi eae af orm
Jn ene is played by veltsge in the other, nd vise ers. Coneide hal this
tea ie the eae of a cenaciance im which east ard vilage se ela
Ty the equation
@ ok
Inverctansing the sof car aml ollie rie replacing inthis
equtin i ae saree ey of. The vale ferns how m3
Soltsnvu he ctilener ane tres Un at ampere thong ie
(Making rink salutes gies
ra tig
i) veh
“This, bowere, isthe kind of equation whea hts the cureat thee
sm indusance fo the volage across it ee soon, Corfe thet the dual!
Slapuadin ne Cb an incertae ae ges by
® renee.
I the da ranean own very caja fn the oxi
netwolf ty ry fear eeicanee fn te. doa
eter, lz, if rand fe represen the voltage acts 9 epacitanee and
‘aasenton emecie mnsnes 387
be curt desu it in te Kite equations of she aviginal men,
ete quaes wil he =ep.aced by, abe: respective, inthe Kitcoll
fey of he cual neswork. ‘The ances sey and", tepecent the
‘cnrnt thrgh an inalatie ofa give by (Dea the viage neon
"Tn angumest just given can esualy wel be ssesreted to meen tat
the dal oa ullance fen espacstanee (the vk oF wes ie geen
by
@ cane,
an that every ex and isin the Richa equations of the original network
ae replaced by fr, and ew, respectively tthe Kirckoff equations ofthe
Aad teen
“The dual ofa resistance fod in the same way. Te equal ap
plicable to resistin
6 oR,
‘wie, with te sbatusion of
efor a ef for becomes,
o B= dfn
“Ts it seen that a tesitance A transforms ino resists A where
oy Wea rt
‘Aly df athe Kisco ecuations ofthe ogi] actwork ace epee
ty tyes and eq, eopectvely, nthe Kischot equations of the duel ret
work.
"The that of a temperature sestive evince hich chara whe with
esngee in average sien! level ean be fd lip exchsagrg the labels on
he exes of am BT pt of ie chametersi. Ts shows i Veo
sesbtance which bas a poste ferrperatare efile al bene eres
sp reistnee with increase in sal level ia resstince with @ sexative
temperature ceticient al mastiner wich Germs in wesiane with
Fnerear in sgl level Silly, the dil oi «sore ale gate
rectance ivan open-cicul- sable nayalive xabtance
‘iw equations applicable to an Heal rinse of inpedance ratio
tatare
% em anya
‘Making the aubaticutions previously indents leads to
uo fe = eye
S85 wy sess neces Joravar, APR ID5L
ste
eed “
a rosie, “Ra0en
(oar canes sare as Aaa Te Aree
sR AIRY
Ree ER
(et) sence
Ga amen br wmaemer
540m ey seerng excuse, yormvas, ae 1951
This indzatay Gist the dual wf an ideal tramsormer of Smpedanoe rain
Iie in another Gal teaeformes wf apsdanee rao aL. It flows that
hedge of 11 Seal tanec Bs 11 thal (ansforme,
“Whe ceal ofa contest wulage supply Fs, of oes «current upply
hic tans constant erent equal to
i) Hawn
andthe dual of» constant wareet supply is supply of constant voltage
cc
0 were
1g. 2The al wma fds asin he Kil ot
‘The proashie of saletitation wed ia all he example above can de
used ja staightdoreand oy tne the duc of 2 more complicate net
Ivor, I in vw af wt sare ee said some labor can be saved
Dy ellis the Kicholl gusto a Ue bbieviter notation sed in ig
2. The equations on the ell corspendizg tothe vigil ebork ae ther
tansformed ito the eealoncod the al net by making hello
stiatontt
From thee (rsforsed equations, shown om Uh ight band aide of Fig 2,
‘hes! ela sown above them et he ean by inspection
