CMOS OTA-C high-frequency sinusoidal oscillators

160 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 26, NO. 2, FEBRUARY 1991 REFERENCES [1] H. K. Gummel and H. C. Poon, “An in eg al cha ge con ol model o bipola ansis o s,” Bell Sys . Tech. J., ol. 49, p. 827, 1970. [2] L. W. Nagel, “SPICE2: A compu e p og am o simula e semi- conduc o ci cui s,” Elec on. Res. Lab., Uni . Cali ., Be keley, Memo. ERL-M50, May 1975. [3] D. E. Thomas and J. L. Moll, “Junc ion ansis o sho -ci cui cu en gain and phase de e mina ion,” P oc. IRE, ol. 46, no. 6, pp. 1177-1184, June 1958. [4] M. K. Chen, F. A. Lindholm, and B. S. Wu, “Compa ison and ex ension o ecen one-dimensional ansis o models,” IEEE T ans. Elec on De ices, ol. 35, pp. 1096-1106, June 1988. [5] M. K. Chen, F. A. Lindholm, and T. W. Jung, “Non-quasi-s a ic small-signal models o semiconduc o junc ion diodes wi h ex ensions o ansis o s,” Solid-s a e Elec on., ol. 30, no. 8, [6] H. Nose and A. W. Wiede , “The ansien in eg al cha ge con ol ela ion-A no el o mula ion o he cu en s in a bipola ansis o ,” IEEE T ans. Elec on Deuices, ol. ED-34, no. 5, pp. 1090-1099, May 1987. [7] J. G. Fossum and S. Vee a agha an, “Pa i ioned-cha ge-based modeling o bipola ansis o s o non-quasi-s a ic ci cui simu- la ion,” IEEE Elec on De ice Le ., ol. EDL-7, pp. 652-654, Dec. 1986. [8] B. S. Wu and F. A. Lindholm, “One-dimensional non-quasi- s a ic models o a bi a ily and hea ily doped quasi-neu al laye s in bipola ansis o s,” IEEE T ans. Elec on De ices, ol. 36, no. 4, pp. 727-737, Ap . 1989. [9] J. A. Sei chik, A. Cha e jee, and P. Yang, “An accu a e pp. 883-885, 1987. bipola model o la ge-signal ansien and ac applica ion,” in IEDM Tech. Dig., 1987, pp. 244-247. [lo] J. E. Schu -Aine, “De e mina ion o a small-signal model o ion-implan ed mic owa e ansis o s,” IEEE T ans. Elec on De ices, ol. ED-30, no. 7, pp. 750-758, July 1983. 111 R. G. Gough, “High- equency ansis o modeling o ci cui simula ion,” IEEE J. Solid-s a e Ci cui s, ol. SC-17, no. 4, pp. 121 A. B. Macnee and R. J. Talsky, “High- equency ansis o model o ci cui design,” IEEE J. Solid-s a e Ci cui s, ol. 131 R. I. Ohs and S. J. Ra ne , “Compu e -aided design and op imiza ion o a b oad-band high equency monoli hic ampli- ie ,” IEEE J. Solid-s a e Ci cui s, ol. SC-7, pp. 487-492, Dec. 1972. [14] S. Kakihana and P. H. Wang, “Simple CAD echnique o de elop high- equency ansis o s,” IEEE J. Solid-s a e Ci - cui s, ol. SC-6, no. 4, pp. 236-243, Aug. 1971. [15] J. Lange and W. N. Ca , “An applica ion o de ice modeling o mic owa e powe ansis o s,” IEEE J. Solid-s a e Ci cui s, ol. SC-7, no. 1, pp. 71-80, Feb. 1972. [16] M. K. Chen, “Me hods o de eloping and assessing ci cui models o bipola diodes and ansis o s,” Ph.D. disse a ion, Uni . o Flo ida, Gaines ille, 1989, chs. 4 and 9. [17] A. B. G ebene, Bipola and MOS Analog In eg a ed Ci cui Design. [18] W. F. Da is, “Bipola design conside a ions o he au omo i e en i onmen ,” IEEE J. Solid-s a e Ci cui s, ol. SC-8, pp. 419-426, Dec. 1973. [19] P. R. Mo z and W. A. Vincen , “Au omo i e elec onics: De- signing cus om ICs o a ha sh en i onmen ,” in hoc. IEEE Cus om In eg a ed Ci cui s Con , 1983, pp. 392-398. 666-670, Aug. 1982. SC-6, pp. 320-322, Aug. 1972. New Yo k: Wiley, 1984, pp. 220-223. CMOS OTA-C High-F equency Sinusoidal Oscilla o s Be nab6 Lina es-Ba anco, Angel Rod iguez-VBzquez, Edga S6nchez-Sinencio, and Jos6 L. Hue as Abs ac -Se e al opology amilies a e gi en o implemen p ac ical CMOS sinusoidal oscilla o s by using ope a ional ansconduc ance ampli ie -capaci o (OTA-C) echniques. Design echniques a e p o- posed aking in o accoun he CMOS OTA’s dominan nonideali ies. Building blocks a e p esen ed o ampli ude con ol, bo h by AGC schemes and by limi a ion schemes. Expe imen al esul s om 3- and 2-pm CMOS (MOSIS) p o o ypes showing oscilla ion equencies up o 69 MHz a e ob ained. The ampli udes can he adjus ed be ween 1 V peak o peak and 100 mV peak o peak. To al ha monic dis o ions om 2.8% down o 0.2% ha e been expe imen ally measu ed in he labo a o y. I. INTRODUCTION HE USE OF ci cui s composed o ope a ional anscon- T duc ance ampli ie s and capaci o s (OTA-C’s) has been Manusc ip ecei ed Ma ch 8, 1990; e ised Sep embe 12, 1990. B. Lina es-Ba anco, A. Rod iguez-Vizquez, and J. L. Hue as we e suppo ed by he Spanish CICYT unde Con ac ME87-0004. B. Lina es-Ba anco is wi h he Depa men o Elec ical Enginee - ing, Texas A&M Uni e si y, College S a ion, TX 77843 and he Depa - men o de Diseho Analbgico, Cen o Nacional de Mic oelec 6nica, Uni e sidad de Se illa, 41012 Se illa, Spain. A. Rod iguez-Vizquez and J. L. Hue as a e wi h he Depa men o de Diseiio Anal6gico, Cen o Nacional de Mic oelec 6nica, Uni e si- dad de Se illa, 41012 Se illa, Spain. E. Sinchez-Sinencio is wi h he Depa men o Elec ical Enginee - ing, Texas A&M Uni e si y, College S a ion, TX 77843. IEEE Log Numbe 9041203. demons a ed o be po en ially ad an ageous o he syn he- sis o high- equency con inuous- ime monoli hic analog op- e a o s, ei he linea [1]-[4], [ll] o nonlinea [5]. One basic eason o he high- equency po en ial o hese ci cui s comes om he ac ha he OTA is used in a local open loop. I means ha no addi ional cons ain s a e imposed on he equency esponse due o local eedback-induced pole displacemen s [2]. Ano he ad an age o open-loop OTA- based ci cui s is ha he ansconduc ance gain o he OTA is used as a design pa ame e . In a ypical OTA a chi ec u e [12], his gain can be adjus ed ei he by changing he ail cu en o a di e en ial pai ( ine adjus men ) o by using digi ally con olled cu en mi o s (coa se adjus men ) [4]. P og ammabili y is hence an inhe en p ope y o OTA-C ci cui s. Based upon he p e ious conside a ions, i may be expec ed ha he ansconduc ance ampli ie -capaci o os- cilla o s (TACO’s) o e come he limi a ions in equency and unabili y o con en ional op-amp-based RC-ac i e oscilla- o s. TACO’s could hen be applied o he design o high- equency ol age-con olled sinusoidal oscilla o s (VCO’s) wi h po en ial applica ion in communica ion sys ems [6] and in he uning o ac i e il e s [l]. In a companion pape [7] he au ho s ha e explo ed he syn hesis o TACO’s om classical oscilla o models, namely quad a u e and bandpass- based. The expe imen al esul s measu ed om disc e e 0018-9200/91/0200-0160$01 .OO 0 1991 IEEE 161 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 26, NO. 2, FEBRUARY 1991 LA -- Fig. 1. Gene al opology o he gene a ion o second-o de OTA-C oscilla o s. bipola p o o ypes showed good po en ial o he TACO'S o high- equency VCO's. Also, a 3-pm CMOS TACO includ- ing a limi ing mechanism o con olling he ampli ude has been epo ed [8] exhibi ing a 10-MHz equency and THD down o 0.2%. In his pape we i s p esen a numbe o new a chi ec u es ha can be sys ema ically ob ained om a gene al idealized TACO opology [9] and hen p o ide expe - imen al esul s o 2- and 3-pm CMOS p o o ypes up o 69 and 56 MHz, espec i ely. The esul s demons a e ha i is possible o implemen high- equency monoli hic VCO oscil- la o s based on simple OTA-C echniques and he modeling o he dominan OTA pa asi ic e ec s [3], [7]. Fu he mo e, we show ha based on a gene al TACO s uc u e, con en- ional and uncon en ional s uc u es can be de i ed. 11. OTA-C OSCILLATOR STRUCTURES ideally desc ibed by a second-o de cha ac e is ic equa ion: In his pape we a e ocusing on oscilla o s which can be s2 - bs + li = 0. (1) Fig. 1 shows a gene al opology o a second-o de OTA-C oscilla o s uc u e [9]. The ol age-con olled cu en sou ces in his opology, N N I,= c gllK I2 = c g2lK ( 2) i=l i=l can be implemen ed by connec ing OTAs in pa allel, one pe each di e en e m in (2). Pa ame e s b and Cli a e gi en as unc ions o he OTA ansconduc ance gains g,, and capaci o alues. The basic TACO design goal is o achie e sepa a e con ol o hese o me pa ame e s wi h a minimum componen coun . We ha e sys ema ically ob ained di e en opologies om Fig. 1 o p o ide his ea u e. Some o he mo e in e es ing and p ac ical ones a e shown in Fig. 2. The co esponding ex- p essions o b and li a e gi en in Table I. These s uc u es in ol e a ade-o be ween complexi y and deg ees o ee- dom. A one end we will ha e s uc u es wi h a minimum numbe o componen s bu wi h a e y limi ed deg ee o eedom. A he o he , he s uc u es will ha e la ge compo- nen coun s and mo e deg ees o eedom. Ne e heless, we belie e i is wo hwhile o include he di e en s uc u es since hey a e applica ion dependen . Ideally, o oscilla ion, he ansconduc ance gains o Fig. 2 mus be immed o yield b =O. Howe e , in p ac ical oscilla o s, due o he in luence o pa asi ics, he poles a e displaced om hei nominal posi ions (sp = jn,) o ei he he igh o he le side o he complex equency plane. Fo ha eason, he oscilla o mus be designed o ha e i s poles ini ially loca ed inside he igh -hal complex equency plane in o de o assu e sel -s a ing ope a ion, i.e., b E, and E is TABLE I STRUCTURES IDEAL EXPRESSIONS OF b AND FOR THE DIFFERENT TACO a sligh ly posi i e numbe [6]. Besides, nonlinea i ies ha e o be conside ed o explain he exis ence o s able oscilla ions. Using he na u al nonlinea sa u a ion cha ac e is ics o he OTA is he simples o m o limi e . Connec ing a nonlinea esis o wi h a d i ing-poin cha ac e is ic [7] is ano he app oach p o iding be e con ollabili y. Finally, exploi ing he bias e minals o he OTA's o implemen an au oma ic gain con ol (AGC) mechanism is a mo e sophis ica ed scheme equi ing addi ional ci cui y bu p o iding educed ha monic dis o ion. These wo la e al e na i es, ex e nal limi a ion and AGC, ha e been used in he p ac ical imple- men a ions included he ein. 111. INFLUENCE OF OTA PARASITICS In Table I we assume ha he OTA pe o ms as an ideal ol age-con olled cu en sou ce. Some expe imen al e o s can be expec ed as a consequence o using such an ideal model. Fo ex eme equencies (bo h high and low) he esul ing e o s a e e y la ge o be ole a ed. Hence, o accu a e TACO design a hese ex eme equencies, OTA pa asi ics canno be igno ed in analyzing he p oposed s uc- u es. Expe imen al obse a ions [7], [ 101 e eal ha only h ee pa asi ics ha e o be conside ed o ob ain a alid design echnique up o a leas 69 MHz, as is demons a ed in he expe imen al esul s included in his pape : a) ou pu conduc ance Go,, 1 Q j Q 4, b) ou pu and inpu capaci ances, and c) ansconduc ance equency dependency, g,, The ollowing cha ac e is ic equa ion is ob ained by using he desc ibing unc ion app oach and conside ing he in lu- ence o pa asi ics: g mi 4s) = gmj(l - s/wj), 1 G j Q 4. s2 - b,s + li, = 0 (3) whe e b, and Szi, a e unc ions o he ansconduc ances g,,(l Q j Q 4), capaci ances Ci(l Q i Q 3), ou pu conduc- ances GOj(l < j Q 4), and pa asi ic ze os wj(l < j < 4). ,. 162 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 26, NO. 2, FEBRUARY 1991 -J / I -- -- (e) Fig. 2. OTA-C oscilla o s uc u es: (a) 20TA3C, (b) 30TA2C, (c) 40TA2C, (d) quad a u e, and (e) 4OTA4C. Pa asi ics make he TACO oscilla ion condi ion b, and he oscilla o equency Cl:, depend on all he ansconduc ance gains. I means ha any in en o change Cl;, by any ansconduc ance gain will also p oduce a change in b, and, hence, in he ampli ude o he oscilla ions. Fo ins ance, in he 4OTA2C TACO, we can, ideally, change Cl:, ia g,, and gm2, wi hou a ec ing b. Howe e , when pa asi ics a e aken in o accoun , g,, and g,, mus also be uned o main ain b, cons an . The in luence o pa asi ics can be assessed om Fig. 3 co esponding o he 40TA2C TACO. Fig. 3(a) shows imming cu es o he ansconduc ance gains o he VCO ope a ion and assuming he OTA’s a e ideal. Fig. 3(b) plo s he co esponding cu es in he case whe e pa asi ics a e aken in o accoun . Obse e ha one o he ansconduc ance gains g,, o g,, can be made ze o a any equency. Fo low equencies i is possible o make g,, = 0 while a high equencies g,, = 0. A low equen- cies, he ou pu impedance (i.e., he OTA ol age gain) o he OTA’s makes he oscilla o de ia e om he ideal (non- pa asi ic) beha io , while a high equencies, i is he ansconduc ance equency dependence (excess phase) ha p oduces he de ia ion. A way o a oid pe o mance deg a- da ion due o pa asi ics and hence o yield high equencies om he p oposed TACO’S is o use a p edis o ion ech- nique based on he analysis o he pa asi ic’s in luence. We ha e used his me hod. The expe imen al esul s we ha e ob ained con i m he alidi y o ou app oach. IV. EXPERIMENTAL RESULTS Th ee oscilla o mic ochips we e designed and ab ica ed in he CMOS p-well p ocess, ei he 3-pm double me al o 2-pm double me al and double poly ( h ough and hanks o MOSIS). Fi s P o o ype: The p ime objec i e o his i s p o o ype, ab ica ed in he 3-pm double-me al p ocess, was o ob ain a high enough oscilla ing equency so ha i could be consid- e ed a adio equency. To ul ill his equi emen , an OTA wi h a e y high ansconduc ance g, was needed. The OTA o Fig. 4 was designed o his pu pose. No e ha he a chi ec u e is a e y simple one. The eason is ha i can p o ide la ge uning anges han linea ized OTAs. On he o he hand, since his OTA is going o be biased by a e y la ge ail cu en (up o almos 10 mA), he e is no need o a linea iza ion scheme. Table I1 shows he basic dc pa ame- e s o his OTA as a unc ion o he bias ol age. The IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 26, NO. 2, FEBRUARY 1991 163 Ro 2.77 kR 3.00 kR 3.78 kR 6.85 kR 9.47 kn 13.82 kR 18.91 kR 48.50 kR 101.00 kR 10-3 10-4 10-~ 10-6 gm 2.49 mmhos 2.38 mmhos 2.12 mmhos 1.90 mmhos 1.76 mmhos 1.61 mmhos 1.43 mmhos 0.932 mmhos 0.638 mmhos ' ( Hz) 10-3 10-4 10-~ 10-6 TABLE I1 EXPERIMENTAL CHARACTERIZATION OF OTA I/bias - 2.72 - 2.98 - 3.19 - 3.40 - 3.51 - 3.61 - 3.68 - 3.80 - 3.88 Ib 9.65 mA 9.60 mA 9.30 mA 6.10 mA 4.20 mA 2.70 mA 1.75 mA 780 pA 490 pA TABLE 111 EXPERIMENTAL CHARACTERIZATION OF OSCILLATOR F equency OTAl OTA2 OTA4 -2.9 V -3.19V - 3.40 V -3.51 V -3.61 V - 3.68 V - 3.80 V - 3.88 V - 3.96 V - 3.98 V - 3.39 56.1 MHz - 3.35 55.5 MHz 50.5 MHz - 3.35 - 3.37 46.1 MHz 40.9 MHz -3.41 V -3.51 V 38.2 MHz 31.3 MHz 24.3 MHz 12.4 MHz 12.0 MHz - 3.66 V - 3.80 V - 3.84 V - 3.86 V 105 106 107 ld 109 (Hz) Red F equency (b) Fig. 3. Tuning o he g,'s o he VCO ope a ion using he 40TA2C: (a) wi hou pa asi ics, and (b) wi h pa asi ics. I I Fig. 4. A 3-pm CMOS OTA. oscilla o s uc u e buil was a quad a u e oscilla o (see Fig. 2(d)), in which he OTA o ansconduc ance g,, was sup- p essed acco ding o he p edis o ion echnique ha esul s om he OTA pa asi ic's in luence, as is shown in Fig. 3(b). Ex e nal limi e s we e included o con ol he ampli ude. The equency o he oscilla o could be uned be ween 12.0 and 56.1 MHz. The dis o ion measu ed a 56.1 MHz was 2.5%. In Table I11 he dependence o he oscilla ion e- quency on he biasing (see Vbia in Fig. 4) o he OTA's is shown. Acco ding o he pa asi ics' in luence, he ela ion be ween oscilla ing equency (R, = 2a o), ansconduc- ance gmi o he di e en OTA's, capaci o s (Cl=C2 = pa asi ic pole wi o gmi) is gi en o his oscilla o s uc u e by 1101 (4) gmlgm2 + Go2(gm4 + + '04) a; = To e i y he accu acy o his exp ession, le us ocus on Table I11 o he case o 24.3 MHz o oscilla ing equency. Fo his case, g,, = g,, = 0.64 mmhos, gm4 = 0.93 mmhos, Go;' = Go;' = 101 kR, Goy1 = 48.5 kR, C, = C, = 5 pF, and wl= w2 =w4= 2a X75 MHz. Acco ding o (4) his would yield a equency o no o - = 26 MHz 2a (5) which is e y close o he 24.3 MHz expe imen ally mea- su ed. Second P o o ype: A second mic ochip was ab ica ed in he 2-pm double-poly, double-me al p ocess in o de o es he model oscilla o s uc u es p oposed in his pape . The chip con ains he h ee oscilla o s 20TA3C, 40TA2C, and 4OTA4C. This ime a linea ized OTA was used, as p oposed by Nedungadi and Geige [11]. The maximum bias cu en o he di e en ial pai s age is less han 2 mA. To ob ain la ge gm alues an addi ional cu en gain was added a he ou pu cu en mi o s. In all hese cases, he ampli ude was con olled by limi a ion, using he CMOS nonlinea esis o o Fig. 5 [8], [lo]. The maximum equencies measu ed o he 20TA3C, 40TA2C, and 40TA4C we e 45.5, 49.8, and 69.0 MHz, espec i ely. Fig. 6 illus a es he a ia ion o he equency wi h he OTA bias ol age o each s uc u e. Thi d P o o ype: A hi d mic ochip was designed in o de o e alua e he pe o mance o an OTA-C oscilla o wi h AGC. A key componen o he success o such a con ol loo^ is a Deak de ec o . The oscilla o will be made o 5 pF), and pa asi ics (ou pu impedances GOi, and dominan ope a e be ween 3 and 13 MHz, app oxima ely. In o de o ., 164 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 26, NO. 2, FEBRUARY 1991 TI - i - Fig. 5. CMOS implemen a ion o he limi e . 4OTAZC //, 2OTA3C I 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 35. gm ("W Fig. 6. Oscilla ion equency e sus OTA ansconduc ances o 2OTA3C, 40TA2C, and 40TA4C oscilla o s. I +5 Fig. 7. CMOS peak de ec o . ou pu * Peak Dcl cb Fig. 8. 40TA2C oscilla o wi h AGC. he peak de ec o o co e his ange and ope a e well a hese equencies a e y simple ci cui was chosen, as shown in Fig. 7. The pe o mance o his peak de ec o was mea- su ed sepa a ely. By e uning he bias e minals I/bias and Vdischa ge (see Fig. 7), he peak de ec o was able o ex ac a 1-MHz signal om a 40-MHz ca ie , a 250-kHz signal om a 1-MHz ca ie , o a 300-Hz signal om a 10-kHz ca ie [lo]. The oscilla o s uc u e used was a 4OTA2C, as shown in Fig. 8. The in eg a o and summe , added o he AGC loop in o de o make i s able [lo], a e implemen ed using OTA-C echniques. The ela ionship be ween he oscilla ion equencies and he bias ol age o OTAl and OTA2 is shown in Fig. 9 o di e en alues o he oscilla ion ampli- ude. ~.-.. 1.04 . . -3.9 -3.8 -3.7 -3.6 -3.5 -3.4 -3.3 -3.2 -3.1 -3.0 Bia Vol age (Vol s) Fig. 9. F equency e sus bias ol age o di e en peak ampli udes. V. CONCLUSIONS A gene al app oach o he sys ema ic design o OTA-C oscilla o s uc u es is p esen ed. Some no el oscilla o s a e ob ained and ha e been ab ica ed on silicon. Oscilla ion equencies o up o 69 MHz we e measu ed. A wide- ange simple peak de ec o has been ab ica ed and included in an AGC loop o one o he oscilla o s. The in luence o he OTAs basic pa asi ics is discussed and e i ied in he ope a- IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 26, NO. 2, FEBRUARY 1991 165 ion o he oscilla o s. In summa y, he o e all well-beha ed pe o mance o OTA-C oscilla o s o high equencies has been demons a ed. REFERENCES [l] F. K ummenache and N. Joel, “A 4 MHz CMOS con inuous- ime il e wi h on-chip au oma ic uning,” IEEE J. Solid-s a e Ci cui s, ol. 23, pp. 742-749, June 1988. [2] K. D. Pe e son, A. Nedungadi, and R. L. Geige , “Ampli ie design conside a ions o high equency monoli hic il e s,” in P oc. I987 Eu opean Con . Ci cui Theo y and Design, Sep . [3] H. Ne B ez-Lozano, J. A. Hill, and E. SBnchez-Sinencio, “F equency limi a ions o con inuous- ime OTA-C il e s,” in P oc. IEEE/ZSCAS ’88, ol. 3 (Espoo, Finland), June 1988, pp. [4] K. H. Loh, D. Hise , W. Adams, and R. L. Geige , “A obus digi ally p og ammable and econ igu able monoli hic il e s uc u e,” in P oc. 1989 IEEE In . Symp. Ci cui s and Sys ., May 1989, pp. 110-113. [5] E. SQnchez-Sinencio, J. Rami ez-Angulo, B. Lina es-Ba anco, and A. Rod iguez-VLzquez, “Ope a ional ansconduc ance 1987, pp. 321-326. 2169-2172. 161 171 181 191 1101 1111 [I21 ampli ie -based nonlinea unc ion syn heses,” IEEE J. Solid- S a e Ci cui s, ol. 24, pp. 1576-1586, Dec. 1989. K. K. Cla ke and D. T. Hess, Communica ion Ci cui s: Analysis and Design. Reading MA: Addison Wesley, 1978. A. Rod iguez-VBzquez, B. Lina es-Ba anco, J. L. Hue as, and E. SBnchez-Sinencio, “On he design o ol age con olled sinusoidal oscilla o s using OTAs,” IEEE T ans. Ci cui s Sys ., ol. 37, pp. 198-211, Feb. 1990. B. Lina es-Ba anco, A. Rod iguez-Vkzquez, E. SBnchez- Sinencio, and J. L. Hue as, “10 MHz CMOS OTA-C ol age- con olled quad a u e oscilla o ,” Elec on. Le ., ol. 25, pp. 765-766, June 1989. B. Lina es-Ba anco, A. Rod iguez-VBzquez, J. L. Hue as, E. SBnchez-Sinencio, and J. J. Hoyle, “Gene a ion and design o sinusoidal oscilla o s using OTAs,” in P oc. IEEE / ISCAS ’88, ol. 3 (Espoo, Finland), June 1988, pp. 2863-2866. B. Lina es-Ba anco, “Design o high equency ansconduc- ance mode CMOS ol age con olled oscilla o s,” Ph.D. dis- se a ion, Uni . o Se ille, Se illa, Spain, May 1990 (a ailable in English). A. Nedungadi and R. L. Geige , “High- equency ol age con- olled con inuous- ime low-pass il e using linea ized CMOS in eg a o s,” Elec on. Le ., ol. 22, pp. 729-731, June 1986. P. E. Allen and D. R. Holbe g, CMOS Analog Ci cui Design. New Yo k: Hol , Reinha , Wins on, 1987. Two No el Fully Complemen a y Sel -Biased CMOS Di e en ial Ampli ie s Me1 Bazes Abmuc --Two no el CMOS di e en ial ampli ie s a e p esen ed. Bo h di e om con en ional CMOS di e en ial ampli ie s in ha ing ully complemen a y con igu a ions and in being sel -biased h ough nega i e eedback. The ampli ie s ha e been applied as p ecision high- speed compa a o s in comme cial VLSI CMOS in eg a ed ci cui s. 2) he ampli ie s a e sel -biased h ough nega i e eed- back. These wo di e ences in he ampli ie con igu a ions esul in se e al pe o mance enhancemen s: I. INTRODUCTION HIS b ie pape p esen s wo no el CMOS di e en ial T ampli ie s. The i s di e en ial ampli ie is in ended o applica ions in which he inpu common-mode ange is ela- i ely limi ed; his ampli ie is deno ed a complemen a y sel -biased di e en ial ampli ie (CSDA) [ll. The second di e en ial ampli ie is in ended o applica ions in which he inpu common-mode ange is bounded only by he supply ol ages; his ampli ie is deno ed a e y-wide-common- mode- ange di e en ial ampli ie (VCDA) [2]. The ci cui con igu a ions o bo h ampli ie s di e om hose o con en ional CMOS di e en ial-ampli ie con igu- a ions in wo impo an ways: less sensi i i y o ac i e- egion biasing o a ia ions in capabili y o supplying swi ching cu en s ha a e signi - nominal doubling o di e en ial-mode gain ( + 6 dB). p ocessing, empe a u e, and supply; ican ly g ea e han he quiescen bias cu en ; These pe o mance enhancemen s a e pa icula ly desi able in compa a o applica ions in comme cial digi al CMOS VLSI in eg a ed ci cui s, whe e p ecision, high speed, ease o in e acing o o dina y logic ga es, and consis en ly high p oduc ion yields a e equi ed. Bo h ampli ie s ha e ound applica ion in comme cial CMOS VLSI in eg a ed ci cui s as p ecision compa a o s, as will be discussed below. 1) he ampli ie s a e comple ely complemen a y, i.e., each n- ype de ice ope a es in push-pull ashion wi h a co esponding p- ype de ice; 11. CSDA A. Theo y o Ope a ion A sel -biased, bu noncomplemen a y, CMOS di e en ial ampli ie has been epo ed [3], as has a ully complemen- a y, bu ex e nally biased, CMOS di e en ial ampli ie [4]. Manusc ip ecei ed Ap il 11, 1990; e ised Sep embe 5, 1990. The au ho is wi h In el Is ael, L d., 31015 Hai a, Is ael. IEEE Log Numbe 9041476. O018-9200/~1/0200-0165$01 .OO 0 1991 IEEE