CA3140, CA3140A, CA3140B Types BiMOS Operational Amplifiers With MOS/FET Input, Bipolar Output ‘The CA31408, CAST4OA, and CA3140 ae Integrated circuit operational amplifiers that Combine he edvantoges of high-voltage PMOS Kansistrs with highvltage. bipolar tran {Inors on a single monolith chip. Because fof this unique combination of technoogles, this dove can now provide designers, fo! tho fire tme withthe special perormance features of the CA330 COSIMOS oper tional_amplifis and the versatility of te Tat series of ladustey standard operational amples ‘The CASIO, CADTHOA, and CA140 O:MOS ‘operational amps feature gate protected MOSIFET (PMOS) transistors tn the Input revit to peovie very high input impedance, veryiowinput current and Nghspeed pee {ormanen The CA31406 operates supply voltages from 4 10 44 volts the CASTAOA and CASI40 from 4 40.36 vot ether ingle [dual supply. These operate rps tray pint compra otis ttion, and, aditionally, have aceese term fale for 9 supplementary external capatior if addtional raaoeneycoltoll is deed, “Terminals are also provides for use in api ‘ations requlring input offsetvoltagenuling “The ure of PMOS fol-etfect transistors in the input stage ests in common mode it putwaltage capability downto 0. vlt below MAXIMUM RATINGS, Absolute Maximum Value TeEtWEEN v7 AND V~ TERMINALS) DOIFFERENTIALMODE INPUT VOLTAGE Device oissipaTion Asove seme (OPERATING (ALL TYPES) STORAGE (ALL TYPES) ‘AT bISrANGE 1/96 #1732 NCH (1.5940 791) TOS sy reatures: the negative supply terminal, an important sttribute for singlesupplyappleations. The futur stge utes bipolattenestors and in Studs balan protection apt dara Stowiyvailortograund, nn “Tha CASI40 Series ae the sr esd termi: ‘nal pin-out uted for the "Tay ‘pdustystendard operational amplifier. They sre supplied in ether the stnderd Blend package (T sufi), or in the & IL-CAN (5 suffix). The CASTE0 ie viable in hip form (H suff (CASIAOA and CA31A0 ate aso availabe in an Bead duane plate package (Mini DIPE sufi. The CA31608 fe intended for ‘operation at supply voltages ranging from 4 ‘mium-erede specification and with elactca| limits established for operations over the range from ~68°Cto H125°C. The CA3T40A and CA3140 ar for operation at supply vot ‘oe up to 96 volte (218 alt). The CART4O apes up to 36 vols (218 volts). All yper can boperated safely over the temperature range from 88°C to H125°C The man mv ner wo re (sev eaten 867 mC 265% on ac Le MOSIFET Input Stag {@) Very high input impedance (Zin) — 1.5 72 typ. (b) Very low input curent (I) — 10 pA typ. at £15 V (©) Low inputotset voltage (Vio) — to 2 mV max. (4) Wide common-mode input voltage range (VicR) ~ ¢an bo swung 05 volt Below nepatie Stpolyvologe all (©) Output swing complements input common-mode (©) upped input stage — bipolar ide protected Directly replaces industry type 741 in ‘most applications Includes numerous industry operational amplifier categories such st general-pur- ose, FET input, wideband high ew rate) Operation from 440-44 volts Slagle of Dua supplies Internally compensated (Characterized fr + 15-alt operation and for TTL supoly systems with ‘peration downto 4 vores Wide bandwidth — 4.5 Mie unity spin t= 15 Voc 30V; 37 Mra V igh voltage follower sow rate—8 Vis Fast sotting tie — 1.4 ue typ, 0 10 mV with 8 10Vp.p signal ‘urput swings vo wien 0.2 vor of negative supply ‘Strobable output stage Applications: ' Ground-aferancad singlesupotyamiies in automobile and portable instrumentation Sample and hold amplifiers Lone ration ders/multivbrators \ieroseconds-minutos-hours) Photocurent instrumentation Peak detectors Active fers intrface in § V TTL systems & other low-suppy voltage systems {Al standard operational amplifier applieatons Function senerators = Tone controle Power supple Portable ineruments Intrusion lar systems‘TYPICAL ELECTRICAL CHARACTERISTICS (CA3140, CA3140A, CA3140B Types Ter conbrtions cnanactenisic | ‘vreviey. |oxat4o8| casraoa|caateo | units ra) | (ese |rse stor Setween, emcee ane Samamiso | as | oe | 47 | xo an.vio Top Rane mr is [spe Top Capes Gr ~>+ [se Sunes Ro Ce Exot Web Taawe (See 30 Ese np am)astoe Tow Ts noeees Prev eo [Pa] ae | ‘Seca th ovo Sippy Sour tot «| « | wo | m ink ton [ee Condon Produc (See Fig. 688) as_| as | as | ome Siew Rae fee Fig6) SR Ee Sink Goren From Tea To Terminal Swing 20 | 2m | 20 | mm Super tow Tiansnt Reson Eos oce_| 000 | 000 | Overshoot (See Fig 37) 10 10 10 * Seria Tine Taw as [as [os | (See Fig.t7) | 10" Voltage Follower 4 ‘« i CIRCUIT DESCRIPTION Fin2 ia block dram of the CA3T40 Series PMOS Operation! Amplifiers The input terminals may be operated own 2 (8 'V betom the nepative supply ral Two Claws amplifier stages provide the voltage Shin, ands unique dens AB amplifier ape Drotides the crret guinnachsry t0 drive fowimpedance ads, ‘Abiatng iret provides conta of cacaded Conwtanccuren ow arcu nthe feet and Second ome. The CA3T40 includes an on Chip. phetecompensatng capacitor tha Ts Sutficlet for the unity goin voltage follow br contguretion. tthe CASI40 fy shown in ip Ieeon fi of alifereniatinput sage using PMOS Fiiéetfex aris (09, 010) working intoa mirror pal of bipolar wanstors (O11, G12} fining load testers together ti restors RE through RB. The mor Bait transistors bo function as dferen {ialosingle ended converter to prove bese trent drive to. the second stage. bipolar tranitor (013) Otter ruling, when de Shed, can be effected with 1048 poten tomate connected across terials ad Band with isle am connected to tr na 4, Gascode connected bipear ansrors 2, 05 ae the sonstantcurent sures for the input stage. The bese boing crcl for the constantcuremt sures fe deste sub ‘equenty. The sal odes D2 Dd, 08 pro. Vide gate-oxide protection seit high Soe warvions, 9. sale electric. Second Stage ~ Most ofthe voltage gin in the CASTA0 is provided by the second amp Iie stage, consisting of bipolar transistor {O13 diy conode-conneted load os tance rovded by bipolr tansistore 02, G4 Onchip phase compensation, wfcient for 8 molority of the appletions provided by Gi Adcional Mitesetect compensation {roltott canbe accomplished, when de Shed, by simply connecting a smal capa {itor between terminals 1 and 8. Terminal Seana Ua 0 Tobe ne Suto stage is Auiescene. When terminal 8 ted to. Aegtive supply rai (terminal ) by mecha Gelor elcreal means the output terminal Swings tow, her approxinstely 0 terial potent ‘Output Stage — The CA3140 Series circuits employ 2 broadband ouiput sage tha can Sink foods to the negative supply to compe. ‘mont te capability of the PMOS input tage wien operating ner the negative a, Que {ant current in the emitter follower escade Bruit (A17, O18) i establishes by tan fistors (014, 015) whose base-eurents are “rmirored” to current lowing trough diode Davin the bios ceut ection. When the {CA3140 is operating such that output ter: ia 6 i suring, vara OTB utrent trom the Vi bur (rrminal 7, vie 7, RO, and RNY. Under these conditions, the collector potential of O13 issu ently high to erm the necesary flow of base carent to amiter follower O17 which, In turn, diver O18, 231CA3140, CA3140A, CA3140B Types ELECTRICAL CHARACTERISTICS FOR EQUIPMENT DESIGN When the GASI40 1s operating such thot eva 18V,V—= = 25°C Un we uit trina 8s sng cant to ha SES TEN Vas Ie TA poate ee One ota tanitor O16 the current sinking i lament. Transistor Q16 is mirorconnected to 06, 7, wit corre fed by way oF 2h, CHARACTERISTIC | —caaiaoe cat aia iat and G0) Want O20, tn on as Pie asd by carant flow through Ri, sner tin. | rye. [wo [in] Tom. [in [Wi | Tp, [es D6, ond 14. The yam currents Tron overvoroe, ol] - [os | 2[- [2 | s [| 5 | i [mv] tr convoted ty vatagyinvl sensing. For oa Gres vote Mol — = = urpones of explanation, itis sumed that Input Ofer Curent. hol os | 10 08 | 20 03 | 2 | A | utput terminal 6 is quiescenty established Input Carer. [10 foo [10 | wo] | 10 | so] ov] Sti porntal midpeint between the Ve —— na ppl ra” When outputcurent Sara [sonfoon| — [zo] oon] — [anal roox| — [vw] singade operation i feted, ty Votuse Goin. Aou® FETE T—Tas Taos] — fae] 100] =f S| letor pot of tansstor G19 is crven (See Fas. 4.18) beiom ft quiescent level thereby eau “et ant = tettotetcte te ea on our he jection Rao, MRR |= = = vv] ferminl 6 “Ths he gte tris eee Faroe ca Gof a} — Yas] Manat 2 a ciples wowar the V= bn {Berby reducing the chanel estan of Common Mode 21. at's consecuene, hea isan no rr oe 155 155 155 tenia increase in caren flow hrosgh eee -1s| te | 12 [15 | v2 | 15] v | Bio"hs2° Ge, Be ante baw we ic os +s +38 8. ‘As rent, GB sinks erent from (Se 9.20) termina 6 in direct respons tothe nse. Fearon fatal change in output voltage cased by Taree” aoiaw | — | 32 | 100] — | 100 | 160| — | r00 | 150 | avov] St shi ok conan flows tyres of aa load any exces current internal supped a, wto]-js|o|-|sfeo @ | bythe emiterfollowe O18" Shortereut in brotecton ofthe output ecu provided aon 1) G19, whch eden Int conduction by oer wt Lali | foal ae | foe] | the high volte top developed arom RTF ¥ vout_| +2 2} 3 | tnderoutputshortercit conditions Under (So 05.192 Yon= | -14[-taa] = | te] 10 vara Soe ener e eencaar or asta py Gren F torts crrent. from 4 40s to vedic the Facies ate 4 |e] | 4 | 6 |ma | tosecurrent drive from O17, thereby limit: Fin ing arent low in O18 to the short. Deve Disarm Po | = [a [imo] — | ae Pwo] — | veo | veo fmm] ced tod emia 5 Bias Creat — Quiescent crrnt in al stage Tout Cart, wo [a|-| of -|[o ae {except the dymami curent nk) of he Se Fig10) CASIAO “is dependent pon bles carent ipeaiomar flo im Ri. "Tow funeton of the bas Totere Mig =f 9 fof] 2 |=] =| | - [ov | asin caspian moinain contant Mig Sarre fow through O17 06,08 98 Bz frourortatvaniw TT s |-]-] 6 | - | -] 8 | - avrg Dis dodeconnected taste mir ae [b¥e) connected in paral! withthe bse tt jimetons of Oi, G2, snd G3. Bt moy oe was cw | 20x] soon — | - [acon] — | — [soon | — [vw | Somdered se» crretanmpling tae at See) es | too | = | = | 100 | = [= | 100 [=] | iatcay’ aut the bv crvont of Go Insc tape pea vara] a | 70 LS : (va. Q1} fo mein 9 constant arent cut Wow Vv | through 08, G8, B2.” Tho bese cutents in votwse* Vow [=a [aa] — [P= P= P= ff 02."G3 re io determined by constant ry] aoe lnewe ie TET TAT] sirient low Ot, Furtnermoreycurent ny : ode connected raster Deelah Bo votage Gain aous* [as [| [=| [= [ET #] cirri inwansstors 14 na a FALVo = 26Vonp FAV, TAV and Ry =F oer 4 ATA = -889C 10 #125%, VE = 15V, V"= IBV, V0 =26Vp = 240 # arvo= #10, 21 V, a» 2. * aviary, voe2v,(CA3140, CA3140A, CA3140B Types Fin. Scher of CA3140 sr eT en P08 Gain satis rade nih re TYPICAL ELECTRICAL CHARACTERISTICS FOR DESIGN GUIDANCE 0 CHARACTERISTIC Cate | GARTAA | CASED | UNITS Trout Ofc Cron Tol | 07 oo arpa Toor Se Seino oe Fa rane a SS ae oa = a = oo Common Made noun Vonage Ranae Vic 08 v Pint — eats ney volte sche mara = Taxman Durpor Walon vou [3 3 ay E Sink Tom 7 7 7 ma Pry Sana = [= [=[*CA3140, CA3140A, CA3140B Types i310 ~ aunt inpt ro vlogs hun ETE =I Fi19 — Power poly ection to 234 APPLICATIONS CONSIDERATIONS Wide dynamic range of input and output ‘characterises with the most desrable ah ‘nputimpedance character achieved In ‘the CASTA0 by th use of an uniaue design tated upon the PMOS-Bipolar process. Input common-mode voltage range and output Sing eapeoiitie are complementary, slot Ing operation with the single spy down otourvalt. Th wide dynamic range of thes parameters sieo meang that thie device eutable for ‘many sieglesupoly spplications, such 3, {or example, where one input i devon be: low the potential of terminal andthe ‘hea eonee ‘of the output signal mut be ‘maintained — most important considers Ton comparator aplieations OUTPUT CIRCUIT CONSIDERATIONS {Excllnt interfacing with TTL ctcuty is fasiy achieved with a angle 6.2vclt tener Mode connected to terminal 8s shown in Figi2. Ths connection assures that the ‘maximum output signal sing wil not 90 more postive than the zener voltage minut ‘wo base-toamitter voltage drops within the CARHAG, "These valtages are independent fof the operating supply voltage Fi.12 ~ Zener clamping dade connected 19 ‘rma ad oon CaSNeo Fig13 shows output curentsinking caps bilaes of the CASIA0 et orlous Supply voltages. Output voltage Sig te the nega tive supply ral permis ths device 10 oper ate both poner tansitors and. thyristors ‘rectly without the need for Tove shifting fireuty sully associated with the 741 ‘eres of operational amplifies Fig13-~ Voge aru ovtut wars O18 Fig,16 show some typical configurations. Now that aries resistor, Rf used in both Sevioe” Moreover its recommend tat 9 ftrioe diode and shunt diode be ured atthe {thyristor input to prevent large negative Iansentaurge that can appes atthe gate of {hiristors, from damaging the intersted 7 aa ane H 914 Typ memantine OFFSET-VOLTAGE NULLING ‘The inputotfiet voltage can be null by connecting 2 TOKE potentiometer benween {erminals 4 and'8 and returning swipe am to terminal 4, sa Fig 182. Ths techni, hoover gives more adjusiment range than equred’ and theretore, 2 consaerable Dor tion of the potentiometer rotation Is nat fully utized. Typical vals of weriesre- sisters that may be placed at ether end of ‘the potentiometer, ses Fi.18b, to optimize [s utlization range are given inthe table ‘"fypical Electrical Oharacterstes” shown Inthisbuletis. [nalteenate system is shown in Fi. 18e. This Cruit uaes only one sitions! feistor of Spproximately the value shown inthe table. For potentiometers, in which the resistance ‘oes not crop to ro ohms either end af fotation, 9 telue of resistance 10% lower than the vals shown ia the tole should be usd LOW.VOLTAGE OPERATION Operation at total supply woltape as low as Notts is posible withthe CAST4O, A cur ‘ent regulator based upon the PMOS thes. hold voltage mainaing resonable constant (operating current and hones consistent De ‘The low oltage limitation occurs when the ‘upper extreme of the input common-mode ‘voltage range extends downto the voltage at terminal This limit reached at 9 ota upply voltage just Eni 4 volts, The out: [ut voltage range also begins to extn down, Iighr than that of tha input. Fig. 20 shows these Chracteristis and shows that with Dole dil supplies, the lowar extreme of the Input common-mode voltage range below ‘yound potenti,SS (CA3140, CA3140A, CA3140B Types Fig 16 Metro of wing he Voto sinking ‘Siren cans of the Csh40 mre ‘BANDWIDTH AND SLEW RATE For those cass where bandwith reduction ie desired, for example, brosdbond noe ¥e- tction, 30 Fowove, alse be proportionally reduced by ‘ing this seditonaleapactor. Thus, 220% eduction in bandwidth by this tochnigue ‘nil ago reduce the slew rate By about 20%. Fig.17 shows the typical settling time re faved to reach T mor 10 mV ofthe fsa Value for various Tevels of large signal in pute for the voltyeollower and inverting tnitygain amples, ‘Tho exceptionally fest satliog time characeristies shown In Fig 18 ate loge due tothe high combing tion of high gun and wide bandwidth of thecasta0, INPUT CIRCUIT CONSIDERATIONS. [As mentioned previously, the amplifier in- puts ean be ven below the terminal Potential, but serie curentiimiting ce Ettore récommandad to limit the maximum Int terminl current to Iss then 1 mA To ‘rovent damage tothe input protection Moreover, some currenlimiting resistance Should be provided between the inverting input and the output when the CAST40 I ed as unity.gain vatage folower. This Fesistnes ‘pewents the possibilty of ex oe “ pe Fiat? — Inout toe esting tine. remoly_ large inputsignal transients trom forcing» signal trough the inputproteetion network and telly desing the internal Constant-cuvent sure wich could result ‘in postive feedback va the output erin SOD restore stent The typical input eurrent iin the order of 10-pAwien the inputs are contered st nom ral device desiption. As the output supplies toad current, device cssnation wil ieresr, ‘ating the chip temporature ond resulting ‘retested input current F919 shows t¥ temperature for the CASO, tie wellknown that MOSIFET devices ean ‘xtibit sight changes i enaracteisties (fr ‘xample, small changes in nut oft vote Se)" ut to the application of large differ fetal input voltage that are surtamned over tong pericds at elevated temperatures Both applied voltage and temperature ae ealefte these changes. The process is over ‘ible and offset voltage shifts of the oppose polity reverse the offiet. Fig shows the {piel offest voltage change a a function of Various ses voltages at the maximum rating of 128°C {for TOI; at lower temperatures (102 and plartel, for oxamote, at 85°C, this change in vtiage is considerably les. In pica linear apolications, where the ferential voltage is srall nd symmetice, these incremental changes are-of bout the Same magnitude a: thse encountered In an ‘operations! amplitier employing a bipolar onsite input stage SUPER SWEEP FUNCTION GENERATOR | function generator having a wide tuning Fang is shown in Fig.21. The 1,000,000/1 ‘Sluremant range is accomplisied bya single Sarlabe potentiometer or by an auslary ‘avecping inal. The CAI40 fonctions ar & fominverting feed-out amplifier of the W ana 235CA3140, CA3140A, CA3140B Types angular signal developed across the itera capacitor network connected 10 the ‘output of die CASOBDA curren source Buffered wiangular output signals ae then spplied to 2 second CAS0B0 functioning 2s highspeed hysteresis switch. Output fom the sites eturned dvetly back to the P20 Oupuoagavion iy snd ‘pot ape and temper Inu ofthe CA2080A curent source, here: by, completing the poitive Feedback Toop. “The triangular output level is determined by the four 1N918 fvesimitng diode of the Second CASOBO and the resistor ier ne. Work connected to terminal No.2 {input of ‘he CASOGO. These diodes extabi the in put tip level tothe siting stage and, ‘erate, indirectly. determine the anal ‘a of fie cant range Compensation far peopapation delays around the enti loop is provised by ane aunt ment on the input of the CAQDEO, This Sjosment, which provides for 9 constant generator amplitude output, it mort ealy Made while the gonerator Is sweeping, Hig freaueney ramp linearity 1 adjusted by the single 7.2060 pF capacitor in the output oF ‘the CA3D803, 1 mast be emphasized that only the CA: ‘20808 ie characterized for maximum output iineanity in the current generator function METER DRIVER AND BUFFER AMPLIFIER Fig, 2 shows the CA3140 connected a5 2 Imeter driver and buler amplifier. Low ‘riving Impedance ie required of the CA S080 current source to. asure smooth Operation "of the Frequency Adjustment 236 AVN Gaal CRA en || io! BES 1S. ee 1V/O1V and 1 se/01V “Tryge tone test signals, highest frequency > (O15 M2 Note te sight aseymmetry a the thweewecond/eycle signal. This symmetry ied to slightly iterenepoutive sod nega tive integration from the CASOSOA an from the pe board and component leakages 2 the 100" eve Control. This towsving impedance re ‘urement is easly mat by using & CASIO Sonnected 2 voltage follower, More fer, a moter may be placed eros the Input to the CAZOBOA to give logortmie ‘halo indication of the function generators ‘requeney. Dlished bythe means desribed above be {Gauge the output current of the CAAD0OA, Navies approximately one decade for each Sm change in the apie voltage, VAR (Gott between terminal anda of the {CA3080A ofthe function goeratr). There fore, sx decades represent 360-mV change nVase. Now, only the reerance voltage must be tetablisied to 1st the Tower limit on the Ineter.The thes remsining transistor Wom the CAS0B6 Array vied inthe sweep genet ‘Sor are used for this reference voltage. 15 Sion, this reference gonerstor range iment tands to tack ambant temperature ‘oration and thor compensates forthe et fects ofthe normal negative temparature ‘ovificent of the CAROBDA VAge. term nal vlage ‘Another output voltage fram the reference {acking of th lower end of the Frequency Aajustmant Potentometr A largy series fesitance simulates scurrnt sour, sing ‘of the Frequency Adjostment Conte To calibeate this cicult, set the Frequency Adjustment Potentiometer at ie low end “Then adjust the Minimum Ecequency Calor tion Contral forthe lowest frequency, ToCrtmae (CA3140, CA3140A, CA3140B Types Done Marco Fig 24 ~ Suaping goer establish the upper frequency limit set the Frequency Adjustment Potentiometer tote Upper end ond then acest the Mlaximom Freaveney Calibration Contal fr the mat mum Wequency. Because there is inte: the adjustment procedure may be necosry “Two adjustments are used for the meter. ‘The meter senltivity contol sets the mete Jeale width of eh dora, we the meter postion eontrel agusts the pointer on the {ala with nepigible effect on the sensitivity ‘justmane. Thus, she mater senaitvity 93 Iustment control calibrates the meter 50 that It deflects 1,6 of ful scale foreach de ‘ade change in fravency. SINE.WAVE SHAPER ‘The circuit shown in Fig, 23 aes @ CA2140 2 voltage follower in combination with Sodas rom the C019 Array to convert the eiangutar signal from the function gen tater to sinewave Output gral Raving pleily less than 2% THD. The base rr Posing slope is established by the TOKE potentiometer connected betwoen terminals Band 6 of the CASIA0 and the 9:1 K0 ve: Sistor and IDE potentiometer trom tar nal 2 to ground, Two break points ae er. {ablshod by slodes Dy through D4. Paste Teedback vie Dg and Dg establishes the 20 Slope at the maximum and minimum levels of the sine wave, "This technique fe neces Sry secause the voltage follower contig Fation approaches unity gain rather than he {aro gan required to shape the sine wate at “This exeut ean be austed most easily with 2 distortion anayaet but» good fist aprox: Imation one made by comparing te outbut Sot mth thatof a stow wave generator, The imal "slope ie adjusted withthe" pot tiometer Bq, fllowed by a9 adjustment Rar The final slope is established by a0 [ding Ra. theoby adding adational seg tronts that are cantbuted by thee diode. Becaue there some infraction mong ‘hse controle, repetition of the adustment procedure may be necessary SWEEPING GENERATOR Fig, 24 shows 2 sweeping gnerator. Throe GARNO is Used aan integrator, «second fievice is usados e hysteresis sotch that ‘Setermines the sterting and topping point of the nweep. A third CASIAO te ured a 3 Fogartamie: shaping network for the og fneton. Rates and slopes, 25 wll 35 saw oath, tWiengle, and logarithmic sweeps are ‘generated by this et WIDEBAND OUTPUT AMPLIFIER Fig. 25 shows a high sew rate, widebond plifir suitable Tor use or 2 S0-chm tans Ison tine eriver_ This evi, when used In conjunction with the function generator and sinewave shaper dius shown in Fig 21 and. 23 provides 1B volts poakto-pesk ‘urput open reuited,o 9 vols peak to Peak fuput when termined in 50. ohms The Slew rato required of this amplifar 28 Voltsgs (18 volts peakto-peak Fx 08 ay 237CA3140, CA3140A, CA3140B Types POWER SUPPLIES Bitty down to the negative supply and igh {ort in the daign of wide-range autputvolt ‘ae supplies that urea sgl input voltage te provide a replated output voltage thet an be adjusted fram esentaly Oto 24 volte Unlike many regulator system using com frtors having. 2 bipolrtensistorinput tape, «highimpedance reference votage ‘ide fom single supply canbe used neon nection withthe CASTAD (ae Fi, 26, Essentially, the regulators, shown in Fis 27 and 28, sre connected os oriverting power operational amplifiers witha gain of BE An Galt referenos. input viele 8 ‘maximum output voltage slghtly” greater than 25 volts. Ae 2 voltage follower when the reference input goes 20” 0 wots the Dutput ll be 0 volts. Because the off Set voltage it alo muitiplies by the 32 {sin factor, 2 pottiometer i netded t0 ful the ofa otage ‘Serie past transistors with high Iogo levels wil abo. prevent the output voltage from reaching er because theres finite voltage trop (Vcesnt) across the output of the Gn3140 Gee Fig’). This saturation vole Soe level may indeed set the lows volt ‘oe btainaba ‘The high impedance presented by termina is advontagnous in effecting curren imi Ing. "Thus, ony a sal signal tansstor Is 238, Fig 27 ~ Replted pom spo rete fr the curentinitsonsing amp i sie ecuning sve To ths rant to munimize datage toi of the CASI&0 in the sant of anusul input or ‘output andes onthe supply ral Fig. 27 and 28, show circuits in which 0 12201 highspeed aoe is used for the urtent enzo’ This diode ws chosen for tt Signy higher foarte srop crac toric thupving restr sett must br emphasizes thet heat inking of tis the diode, That is, 1 ampere a0 T volt forward drop represents one watt whieh Coe re to tgnict generate changes inthe curenttip point asthe sia tom porate res: Plcing the salagal ee. nee amplifier in the proximity ofthe eur Sentara lode oho rime the ‘erably ithe wip level Sue to he neg The temperate costcent of the olde, In epte of thos limitations, the curent limiting point ean easly be sdjusted over the range ram 10 mA to. T ompete with finger astment potentiometer the Fig 29 novatarsot aUsual currentsampling resistortype of ei fuley should be employed A power Darlington wansator (in a heat fink TO.3 cae), i wed a¢ ho seis pst ‘lament forthe conventional current limiting fystom, Fig 27, because high-power” Dar ington dissipation will be encountered at low output vltage and high eurant. ‘A small heatsink VERSAWATT transistor Used a the series pass element in the fold back “current system, Fig28, since dis ation levels will only approach 10 watt Ih system, the 02201 ciode is used for futent simpli. Foloback ve proviced BY the 3 kit and 100 KB diviger network con fected tothe base of the curentsensina ‘oth regulators, Fig. 27 and 28, provide Dette ‘thn 0.03% load regulation” Because there is constant loop gain at ll voltage set tings, the regulation also remains constant. tine regulation is 0.1% per alt. Hum and ois ‘voltage is lest than” 200 JV at read ‘with a eter having a TOMHz bandwidth, gto) shows the turn ON and wen OFF characteristics ofboth regulators. The slow turn-on rise ue to the sow rate of tae fof the veference voltage. Fig. 29 [b) shows the transient response of the regulator with the switching of 2 2021 load at 20 vols out. TONE CONTROL CIRCUITS High siwate, wide bandwidth, high-output ‘oltageeapabity and high input impedance ‘Se all characteristics required of tone-con {rol amples. Two tone contol outs that “explo thesecharoctoriie. of he {CAI140 are shown in Figs 30 ane 31. The first cout, shown in Fig. 31,16 the ‘Bdsandall tne-contro\ creurwhich roves Sanitygala at midband. and uses standard Tinear potentiometers The high input im cance of the CASTAO mskes posible the ors, st wel a raduced load ofthe Sing stage Bass treble boost and cut ate #18 dB at 100 He and. 10 kHz, respectively. Full peak-to-peak output is available up to at Feast 20 kts de to the high wae of he ERG140. The ampiier gains 38 down from te “tat postion a 70 ki Fig. 30 shows another tone-conwol circuit wth sitar boort and. cut spect one ‘The wideband goin of this ereut equal to the ultimate boost or cut plus ne, hi in this care it 2 ann of eleven. For 20.8, boast end eu, the input lasding of thi ci ult is essentially equal 10 the value of the fexstnee from ‘terminal Nod to ground ‘detailed analy of tis cau is ghen in “An IC Operational Transconcictanes Amp liter (OTA) With Power Capability” by kaplan and H. Winger, IEEE rang sctions on Bloadeast and. Television ‘Re hives, Vol. BTA 18, No.3, Auguet, 1972, CA3140, CA3140A, CA3140B Types (2. midbond ui WIEN BRIDGE OSCILLATOR Another application of the CAIT40 that makes excellent use of high input imped noe, high lewrate, and high-voltage Quall- tosis the Wien Bridge sinewave oslotr ‘A basic Win Bridge eseiator ie shown in Fig 32 When Ry = R=Rand Cy =C2=C, the frequency equation reduces 10 the fa Inilar {= 1/2" RC and the gan required for Grellaton, AQge is ual to 3. Note that iF Ca is increased by a factor of four and Fa 's reduced by a factor of four, the gun re ‘ulred for onilation becomes i,t ps ‘iting 2 potentially higher operating te Atueney lor tothe gaimbanddth pro. thet ofthe CAS¥40, ‘Ozilator stabilization takes on many forms In'must be prely se, otherwise the ah plitude. wll either ‘minis or reach some form of iting with high levels of str Hom: The. element, Ris commodly re placed with some variable esatance semen {Thus through some control means, the value OF Ry i adjusted Yo maintain constant oxo lator qutput. A FET channel reistane, 2 thermistor, a lamp bulb, or other device hose restance is made to inerese 9 the utbut amplitude is increased ae 2 few of ‘he elements often ize, Fig 32 base Wie rig oxen cicalt Fig 33 shows another means of stabilizing the oristor with 2 zener ode shunting the feedback Yesstor (Ry of Fig 32), Ae et dle pedir deceniy ein in gun: thos stabilizing the amplitude of te ‘output signa Furthermore, ths combine tion f 3 monolithic zener dade and begs Feetier circuit tends to provide a 20 tem Deratue‘oelticont for this regulating ss tem Because ths bridge recta Fas no time constant, therml tine con ont oe the lamp bulb, and RC time con ont for filters often uied in detector net Works, thera Is. na. lower frequency lim. For example, with 1 uF polyearbonate cape ‘tors end 22 MR for the trequeney deter Imining network, the operating Tequeney is oor He ‘As the thaquency is incrsied, the output Smplitide. must be reduced to prevent te ‘output signal from Becoming sews im tes, “An output frequency of 180 kHz will each sew rate of approximately 9 volt! ise is amp 18 wots peak 239