High input impedance voltage-mode universal filter and its modification as quadrature oscillator using VDDDAs

Transcription

1 Indian Journal of Pure & Applied Phyic ol. 55, May 017, pp High put impedance voltage-mode univeral filter and it modification a quadrature ocillator ug DDDA Sunti Tuntrakool a, Montree Kumngern a, Roman Sotner b, Norbert Herencar c, Peerawut Suwanjan d & Wai Jaikla d a Department of Telecommunication Engeerg, Faculty of Engeerg, Kg Mongkut Intitute of Technology Ladkrabang, Bangkok 1050, Thailand b Department of Radio Electronic, Faculty of Electrical Engeerg and Communication, Brno Univerity of Technology, Brno 61600, Czech Republic c Department of Telecommunication, Faculty of Electrical Engeerg and Communication, Brno Univerity of Technology, Brno 61600, Czech Republic d Department of Engeerg Education, Faculty of Indutrial Education and Technology, Kg Mongkut Intitute of Technology Ladkrabang, Bangkok 1050, Thailand Received 14 July 016; revied 7 December 016; accepted 3 January 017 The econd order univeral voltage-mode filter ug voltage differencg differential difference amplifier (DDDA) ha been propoed. It ha high put impedance voltage-mode biquad filter with orthogonal tune of natural frequency and quality factor. The propoed filter imultaneouly provide five filter repone: low-pa (LP), high-pa (HP), band-reject (BR), all-pa (AP) and band-pa (BP) the ame circuit topology. The natural frequency and quality factor can be tuned electronically and orthogonally dc bia current. The output impedance at output node HP, AP and BR ha low impedance which can connect to other circuit without the ue of voltage buffer. The propoed filter conit of three DDDA, one grounded reitor and two grounded capacitor. Thi make the propoed filter uitable for tegrated circuit development. With lightly modifyg the propoed filter, the voltage-mode qudrature uoidal ocillator with low output impedance and dependent control of condition of ocillation (CO) and frequency of ocillation (FO) ha been achieved. The reult hown thi paper are from PSPICE imulation and experiment to validate the propoed circuit. Keyword: Analog filter, DDDA, oltage-mode, Sgle put-multiple output, Ocillator 1 Introduction The ocillator circuit and analog active filter are popular and tandard topic for circuit deign. They are widely ued for their important requirement for application electrical and electronic ytem and alo very popular ug for circuit deign of contuou-time analog ignal proceg. There are many field that ug filter circuit uch a communication, meaurement, and trumentation, and control ytem 1. Epecially, reearcher have been very coniderably teret everal function filter which i called univeral filter or multifunction filter. The gle-put multiple-output (SIMO) i the mot popular analog filter where different output filter function can be imultaneouly realized by the ame circuit topology. Correpondg author ( wai.ja@kmitl.ac.th) Ug of active buildg block for circuit deign i very popular ue. It give the flexibility for deigner to realize the high performance circuit ug mimum number of active element 3-7. With mentioned feature, the prciple of active buildg block for both current and voltage mode circuit are troduced by Biolek et al. 6 oltage differencg differential difference amplifier (DDDA) 8 i one of the teret. It allow teretg utilization and deign of more profitable or more exactg application epecially the electronic controllability. From literature review, it i found that not much reearch ug DDDA ha been publihed for tance the voltage-mode firt order all pa filter 8, ocillator The excellent multiple-put multipleoutput (MIMO) voltage-mode univeral filter ug DDDA wa propoed literature Thee filter can provide complete tandard tranfer function with

2 TUNTRAKOOL et al.: HIGH INPUT IMPEDANCE OLTAGE-MODE UNIERSAL FILTER 35 high put and low output impedance. The natural frequency and quality factor can be electronically and orthogonally controlled. However, thee filter cannot be conidered a univeral filter becaue all five filter repone cannot be imultaneouly provided. The multiple-put gle-output (MISO) voltage mode filter wa troduced by Herencar et al. 15 Thi filter conit of gle active buildg block, gle MOS tranitor and two floatg capacitor. It can provide five filter repone dependg on the appropriate electg put voltage. The natural frequency and quality factor can be electronically tuned. However, thi filter cannot be eay to cacade without the ue of voltage buffer. Moreover, the ue of floatg capacitor i not attractive for tegration. Thi contribution preent a SIMO voltage-mode filter with high put impedance, emphaizg on ue of DDDA. The propoed filter compoe of three active element, one grounded reitor and two grounded capacitor which are uitable for fabricatg monolithic chip or off-the-helf implementation. The propoed filter can provide five tandard function uch a low-pa, high-pa, band-reject, all-pa and band-pa. The quality factor and natural frequency can be electronically and orthogonally adjuted. With light modification of the propoed filter, the voltage-mode quadrature ocillator with low output impedance i achieved. Prciple of Operation.1 DDDA overview The prciple of DDDA wa troduced by Biolek et al. 6 Later, Herencar et al. 8 propoed the ternal contruction of DDDA ug CMOS technology. Symbol and equivalent circuit of DDDA are hown Fig. 1 (a) and (b), repectively, where + and - are the voltage put termal which will be converted to be the current at z termal by tranconductance (g m). It i generally tuned by bia current and the differential voltage at termal z, n and p will be end to w termal with the unity voltage ga. For ideal DDDA, it ha low output impedance at w termal and high put impedance at termal Fig. 1 DDDA (a) ymbol and (b) equivalent circuit +, -, z, n and p. The characteritic matrix equation of ideal DDDA i decribed below: Iv I v I z gm gm z In n I p p w I w (1). High put impedance voltage-mode filter ug DDDA Figure i the propoed econd order filter conited of three DDDA, one grounded reitor and two grounded capacitor. The propoed filter provide imultaneouly five filter repone; HP, LP, BR, AP and BP (BP 1 and BP ) with high put impedance. Moreover, the output node for HP, AP and BR repone exhibit low output impedance. Coniderg an ideal DDDA, route analyi of the propoed filter provide the followg voltage tranfer function: HP HP() D() () LP() BR() m1 m LP 1 (3) g g C C D() m1 m BR 1 (4) Fig. Preented voltage-mode filter g g C C D()

3 36 INDIAN J PURE & APPL PHYS, OL. 55, MAY 017 AP() m1 m1 m AP 1 1 (5) gm 1 () C BP1 D() g g g C C C D() BP1 1 (6) gm 1gm3R BP C1 (7) BP () D() where g g R g g D() C C C m1 m3 m1 m (8) 1 1 It i found from Eq (-8) that the propoed filter i the unit ga filter, then, for any practical ue, additional voltage amplifier are needed to achieve ga from the active filter. However, the ga i probably obtaed for BP 1 only if pecific quality factor (Q) i et. The natural frequency (ω 0) and Q of each filter repone can be expreed a followg: g g m1 m 0 and 1 g 1 m Q (9) g R C g m3 m1 From Eq. (9), it i found that the quality factor can be electronically tuned via g m3 without affectg the natural frequency. Moreover, if g m1 i equal to g m, the natural frequency can be electronically adjuted without affectg the quality factor. However, it i found that the propoed circuit need component matchg condition (i.e., g m3=1/r) for realizg AP repone. The relative enitivitie of the propoed filter can be found Eq. (10): Sg S ; ; m1 g S m C S Q Q0 Q0 Q0 Q0 Q0 SR Sg 1; S ; m3 C S 1 g S m C S g m1 (10) It i found that the active and paive enitivitie are equal or le than unity magnitude. 3 Non-Ideal Cae Practically, the performance of the propoed filter are affected by the fluence of voltage trackg error from the unity-value ga of ternal differential voltage buffer and paraitic termal impedance of DDDA 8. In thi ection, thee parameter will be taken to account. For non-ideal cae the voltage at w termal i rewritten a hown below: (11) w z z n n p p From Eq. (10), β z, β n, and β p - are the voltage error ga from z, n, p termal to w termal, repectively. The fluence of paraitic impedance of -1, p 1, n and n 3 termal will be negligible becaue of their connection to low-impedance output (w 3 termal) and put voltage ource. The mot importance paraitic impedance are the impedance at z 1 (R z1//c z1), n 1 (R n1//c n1), + (R +//C +), z (R z//c z) and p 3 (R p3//c p3) termal. However, the paraitic impedance at z 3 termal will be negligible but the operation frequency f op hould be more lower than 1/{C z3(r z3+r)}. The voltage tranfer function for the circuit of Fig. 3 are given Eq (1-17): n3 C C1 G CG1 G1 G HP (1) D () n3gm 1gm LP C1C (13) D () z n 3 m 1 m n n3 C C1 G CG1 G1 G (14) 1 BR n3gm1 BP1 C D () D () g g 1 G (15) 1 G (16) n3gm1gm3 R BP C D () AP where n3 C C1 G CG1 G1 G 1 G n3gm 1g m z1n3gm1 C C... (17) D () G G1 z3gm1gm3r C C 1 D () G G g g RG g g 1 1 z3 m1 m3 p3 m1 m (18)

4 TUNTRAKOOL et al.: HIGH INPUT IMPEDANCE OLTAGE-MODE UNIERSAL FILTER 37 C 1 = C 1+C z1+c v++c v+3, G z1+g v++g v+3 and C = C +C z+c n1+c p3, G 1 = G = G z+g n1+g p3. Alo nonideal value of ω 0 and Q are found Eq (19) and (0), repectively: G G g g RG g g (19) 1 z3 m1 m3 p3 m1 m 0 1 Table 1 Dimenion of the tranitor Tranitor W (µm) L (µm) M1-M, NMOS (AGC) M3-M M5-M M8-M M1-M G1 G z3gm 1gm3RG Q C 1C C1 G CG1 p3gm1g m z3c gm 1gm3R (0) 4 Simulation Reult PSPICE imulation of the propoed filter Fig. were performed. The implementation of the CMOS DDDA wa ame a decribed elewhere 8. Parameter of a 0.18 µm TSMC CMO Stechnology 16 (level 7) with ±0.9 voltage upply and B = wa ued for imulation of PMOS and NMOS tranitor. From Table 1, apect ratio of PMOS and NMOS tranitor are lited. It i een that the paraitic reitance at termal +, -, n, and p (R v+, R v-, R n and R p) exhibit high becaue they are gate reitance. Other imulated paraitic element value for each termal (I B = 50 A) are C v+ = 55.5 ff, C v- = 53. ff, R z = k, C z = 15.4 ff, C n = 4.4 ff and C p = 4.5 ff. The imulated voltage error ga, β z, β n, and β p are equal to The filter wa deigned with the parameter of it component a follow: C 1 = C = 47 pf, R = 3.3 k, I B1 = I B = I B3 = 50 µa. It yield the natural frequency of MHz and quality factor of 1. The theoretical pole frequency i about MHz. From the reult, the ga repone for LP, BP 1, BP and HP of the propoed filter obtaed from Fig. are hown Fig 3-5 which are the ga repone and phae repone of BR and AP repone, repectively. It i obviouly that the propoed filter can imultaneouly provide low-pa, high-pa, band-pa, band-reject and all-pa function without modifyg circuit topology. The ga repone of BP difference I B3 i hown Fig. 6, where I B3 wa et to 0 A, 50 A and 00 A. The quality factor evaluated baed on the imulation reult wa 1.49, 1, and 0.65, repectively. Thi i confirmed by Eq. (9) that the quality factor can be electronically tuned by I B3 without affectg the natural frequency. High Q value can be achieved by ettg I B3 a low a poible. The highet imulated Q i 6.66 (I B3 = 1 A) and the lowet imulated Q i (I B3 = 400 A). Fig. 3 Frequency repone of propoed filter LP, BP1, BP and HP Fig. 4 Ga and phae repone of BR Fig. 5 Ga and phae repone of AP Fig. 6 BP repone for difference IB3 Figure 7 how the dependence of the THD of LP filter on put voltage level. The THD i not over 1% when the put ignal i lower 650 m. In thi tet, uoidal ignal with 100 khz -band frequency wa fed to the propoed filter. 5 Comparion with Exitg SIMO oltage-mode Filter The propoed SIMO voltage-mode filter Fig. i compared with everal SIMO voltage-mode filter from It i found from Table that there are M

5 38 INDIAN J PURE & APPL PHYS, OL. 55, MAY 017 MISO tructure havg even ome low-output impedance output 5,9,3,38,4. However, their other drawback are mig poibility for electronic control, requirement for floatg paive element and higher number of active element (4 or 5). All thee problem are olved olution preented thi paper. 6 Modification of Propoed Filter a Quadrature Ocillator By connectg node BP1 to and terconnectg termal + and - of DDDA1 and DDDA of the circuit Fig. accordg to the prciple reported earlier tudy 45 a illutrated Fig. 8, the voltagemode quadrature ocillator with low output impedance can be achieved. The characteritic equation of the ocillator Fig. 8 i obtaed a: g g g g R 1 m m m 0 (1) 1 1 m3 C1C Accordg to Eq. (1), the frequency of ocillator (FO) and condition of ocillation (CO) i written a: Fig. 7 Dependence of output harmonic ditortion of LP filter on the put voltage g g m1 m 0, and 1 gm3 1 R () Table Comparion of variou SIMO voltage-mode filter Reference ABB No. No. Grounded High put Electronic Orthogonal Five filter Low Technology of ABB of R+C element only impedance tune tune of Q and 0 repone output impedance 17 D 3 3+ ye ye no no ye no CMOS 18 D 3 3+ no ye no ye ye no CMOS 19 D 3+ no no no ye ye no CMOS 0 FDII (Fig. 3) 1 + ye ye no no no no CMOS 1 DD 3+ no no no no ye no CMOS DD 3 + no no no no ye no CMOS 3 DD & OTA 1+ ye ye ye no no no CMOS 4 OTA 8 0+ ye ye ye ye no no CMOS 5 CFOA 1 3+ no no no ye no LP commercial IC 6 DDTA 1 1+ ye ye ye no no no CMOS 7 DDTA + ye ye ye no ye no CMOS 8 OTA 8 0+ ye ye ye ye no no CMOS 9 DDTA 3 0+ ye ye ye no ye AP CMOS 30 TA no no ye ye no no BJT 31 DDTA 1 + no no ye no no no CMOS 3 DDTA + ye ye ye no ye AP CMOS 33 FDII 1 3+ no no no no ye no CMOS 34 D 4 5+ ye ye no ye no no CMOS 35 III 4+ no no no no no no CMOS 36 D +3 no no no no no no CMOS 37 DDTA + no ye ye ye ye no CMOS 38 D-DIBA 0+ ye ye ye no no HP commercial IC 39 D (Fig. 3) 1 + ye no ye ye no no CMOS 40 D 1 + no no ye ye no no BJT 4CII 3+ no ye no no no no CMOS 4 DDTA 3+ ye ye ye ye ye AP CMOS 43 DTA (Fig. 5) 1 0+ ye ye ye no no no CMOS 44 II 4 5+ no ye no ye ye no commercial IC Preent work DDDA 3 1+ ye ye ye ye ye HP, AP, BR CMOS & commercial IC

6 TUNTRAKOOL et al.: HIGH INPUT IMPEDANCE OLTAGE-MODE UNIERSAL FILTER 39 Fig. 10 Output pectrum Fig. 8 oltage-mode quadrature ocillator with low output impedance It i found from Eq. () that the FO and CO are dependently and electronically controlled. The relationhip of O and O1 i follow: O C1 (3) g g O1 m1 m3 At ocillation frequency ( 0), the magnitude of O/ O1 i written a: O 1 gm (4) g C g O1 m3 m1 0 Fig. 9 Quadrature output waveform It i found from Eq. (4) that the changg of g m1 or g m for controllg the FO caue change of amplitude O and O1 durg tung proce. Thi phenomenon will creae the THD if amplitude reache high level due to the limit of dynamical range of DDDA. However, thi can be alleviated by imultaneouly changg g m1 and g m (I B1 = I B). A tated above, the amplitude of quadrature output Fig. 11 Tung of FO by adjutg IB1 and IB voltage O1 and O i equal for all frequency. However, to unify unbalance of produced amplitude O1 and O a well a to reduce the THD, the imple AGC circuit for amplitude tabilization can be eaily applied to termal z of DDDA3. The propoed ocillator Fig. 8 wa imulated with the parameter of it component; C 1 = C = 47 pf, R = 3.3 k, R p = 330 k, I B1 = I B = 50 µa and I B3 = 51.5 µa. The W/L of NMOS AGC i 9 /1.08 m. It yield the FO of MHz. The theoretical FO i about MHz. The reult of thi imulation are, repectively, hown Fig 9 and 10. The total harmonic ditortion for O1 and O are 0.68 % and 76 %, repectively. Tung of imulated and theoretical FO i hown Fig. 11, where I B1 and I B are equal and were adjuted from 10 A 300 A. The range of FO controlled from 0.31 MHz.4 MHz wa obtaed. It i found that there i ome deviation between theoretical and imulated value due to the paraitic element a analyzed Eq. (19). The tung of g m by adjutg I B will change the value of paraitic element. 7 Experimental Reult The performance of the propoed filter and ocillator were alo experimentally vetigated. The

7 330 INDIAN J PURE & APPL PHYS, OL. 55, MAY 017 Fig. 1 Internal contruction of DDDA contructed from an available commercial IC Fig. 15 Meaurement of BP at frequency 63 khz Fig. 13 Experimental ga repone of the propoed filter Fig. 14 Experimental ga repone of BP for different value of IB3 DDDA wa contructed from the available commercial IC, AD830 and LM13700 a illutrated Fig. 1. The tranconductance of LM13700 i g m = I B / T where T i thermal voltage ( T 6 m at room temperature). The propoed filter wa firtly teted with followg condition; the upply voltage 5, C 1 = C = 5.6 nf, I B1 = I B = I B3 = 115 A Fig. 16 Meaurement of output voltage and it pectrum where IB1 = IB = 115 A (g m1 = g m = g m3 =.11 ma/) and R = 0.45 k. With thee condition, the natural frequency and quality factor are khz and 1, repectively. The experimental ga repone of BP, BP 1, LP, HP, BR and AP i hown Fig. 13. The experimental natural frequency i about 61 khz which wa about.948 % deviated from theoretical value. The tung of Q without affectg natural frequency i confirmed by the experimental reult of BP filter Fig. 14 where the value of I B3 wa changed to 57.5 A, 115 A and 30 A. The meaurement of output voltage BP i alo hown Fig. 15 where the 50 m uoidal voltage with 63 khz of frequency wa applied a put ignal. The propoed ocillator Fig. 8 wa teted with followg condition; the upply voltage 5, C 1 = C = 5.6 nf, I B1 = I B = I B3 = 115 A (g m1 = g m = g m3 =.11 ma/) and R= 0.54 k.

8 TUNTRAKOOL et al.: HIGH INPUT IMPEDANCE OLTAGE-MODE UNIERSAL FILTER 331 With thee condition, the FO i 6.9 khz. Figure 16 how the meaured output voltage where the experimental FO wa about khz which wa about % deviated from theoretical value. It i alo found that the output voltage o1 and o are quadrature uoidal ignal. 8 Concluion oltage-mode bi-quad filter ha been propoed thi tudy. The advantage of the propoed filter are a follow. Firtly, it can perform variety of filter, i.e., low-pa, high-pa, band-pa, band-reject and all-pa function. Secondly, the quality factor and the natural frequency can be electronically and orthogonally controlled. Fally, the filter ha high put impedance. Moreover, the output voltage termal for function high-pa, band-reject and allpa are low output impedance. The propoed filter conit of three DDDA, one grounded reitor and two grounded capacitor, which are attractive for either IC implementation. With lightly modifyg the propoed filter, the voltage-mode quadrature ocillator low output impedance i achieved. The CO and FO can be dependently and electronically tuned. Moreover, the ratio of amplitude O1 and O i contant on the tung of FO if I B1 and I B are imultaneouly tuned. Simulation reult confirmed theoretical anticipation and validity of the ynthei. The power conumption for propoed filter i mw and for propoed ocillator (with AGC circuit) i mw. Moreover, the experimental reult ug available commercial IC (AD830 and LM13700) are cluded and they meet very well with theoretical preumption. Acknowledgement Thi work wa upported by the Kg Mongkut Intitute of Technology Ladkrobong (KMITL), National Reearch Council of Thailand (NRCT), Reearch decribed thi paper wa fanced by Czech Mitry of Education frame of National Sutaability Program under grant LO1401. For reearch, fratructure of the SIX Center wa ued. Reearch decribed the paper wa upported by Czech Science Foundation project under No Y. Reference 1 Sedra A S & Smith K C, Microelectronic circuit, 6 th Edn, (Oxford Univerity Pre, USA), 011. Pychalo C, Analog Integr Circuit Signal Proce, 67 (011) Jantakun A & Jaikla W, Indian J Pure Appl Phy, 53 (015) Chaichana A, Jantakun A, Kumngern M & Jaikla W, Indian J Pure Appl Phy, 53 (015) Yuce E & Maei S, Int J Circuit Theory Appl, 4 (014) Biolek D, Senani R, Biolkova & Kolka Z, Radioengeerg, 17 (008) Kubanek D, Khateb F, Tirimokou G & Pychalo C, Circuit Syt Signal Proce, 35 (016) Herencar N, Sotner R, Met B, Koton J & rba K, DDDA - New 'voltage differencg' device for analog ignal proceg, International Conference on Electrical and Electronic Engeerg, Bura, Turkey, Chaichana A, Jaikla W, Suwanjan, P & Tuntrakool S, A new quadrature uoidal ocillator for telecommunication ytem ug DDDA, International Conference on Intelligent Informatic and Biomedical Science (ICIIBMS), Tuntrakool S, Kumngern M & Jaikla W, DDDA-baed voltage-mode multiphae uoidal ocillator, International Conference on Indutrial Application Engeerg, Koton J, Herencar N, rba K & Met B, The DDDA multifunction filter with mutually dependent Q and ω0 control feature, International Conference on Electrical and Electronic Engeerg (ELECO), Koton J, Herencar N, rba K & Met B, Analog Integr Circuit Signal Proce, 81 (014) Sangyaem S, Siripongdee S, Jaikla W & Khateb F, Optik, 18 (016) Siripongdee S & Jaikla W, Sgle DDDA-baed voltagmode multifunction econd order filter for analog ignal proceg, International Conference on Intelligent Informatic and Biomedical Science (ICIIBMS), Herencar N, Cicekoglu O, Sotner R, Koton J & rba K, Analog Integr Circuit Signal Proce, 76 (013) lo_epi-param.html 17 Maei S & Yuce E, Circuit Syt Signal Proce, 9 (010) Chiu W Y, Horng J W, Lee H & Huang C C, IEEE International Sympoium on Electronic Deign, Tet and Application, Ho Chi Mh City, ietnam, Horng J W, Analog Integr Circuit Signal Proce, 6 (010) Chiu W Y & Horng J W, Indian J Eng Mater Sci, 18 (011) Kacar F & Yeil A, Analog Integr Circuit Signal Proce, 63 (010) 137. Chiu W Y, Horng J W, Guo Y S & Teng C Y, DD baed voltage-mode one put five output biquadratic filter with high put impedance, International Sympoium on Integrated Circuit, Sgapore, Udorn N, Duangmalai D & Noppakarn A, High put impedance current controlled voltage-mode univeral filter ug DD and OTA, IEEE International Conference on ehicular Electronic and Safety (ICES), Kumngern M, Suwanjan P & Dejhan K, Electronically tunable voltage-mode SIMO OTA-C univeral biquad filter, Aia-Pacific Conference on Communication (AP011), Horng J W, Hou C L, Huang W S & Yang D Y, Circuit Syt, (011) Tangrirat W & Channum O, Radioengeerg 0 (011) 905.

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