Current Or/And Voltage-Mode Quadrature Oscillators With Grounded Capacitors And Resistors Using FDCCIIs

Transcription

1 WSEAS TRANSACTIONS n CIRCUITS AND SYSTEMS Jiun-Wei Hrng, Chun-Li Hu, Chun-Ming Chang, Current Or/And Vltage-Mde Quadrature Oscillatrs With Grunded Capacitrs And Resistrs Using FDCCIIs JIUN-WEI HORNG a*, CHUN-LI HOU a, CHUN-MING CHANG b, SHIH-TING CHENG a and HSIN-YU SU a a Department f Electrnic Engineering, Chung Yuan Christian University, Chung-Li, 33, TAIWAN b Department f Electrical Engineering, Chung Yuan Christian University, Chung-Li, 33, TAIWAN * Crrespnding authr. jwhrng@cycu.edu.tw Abstract: - Tw quadrature scillatr circuits each using ne fully differential secnd-generatin current cnveyr (FDCCII), tw grunded capacitrs and tw grunded resistrs are presented. The current-mde quadrature signals can be btained frm the first prpsed circuit. The current-mde and vltage-mde quadrature signals can be simultaneusly btained frm the secnd prpsed circuit. In bth prpsed circuits, the current-mde quadrature signals have the advantage f high utput impedance. The scillatin cnditins and scillatin frequencies are rthgnal cntrllable. The use f nly grunded capacitrs and resistrs makes the prpsed circuits ideal fr integrated circuit implementatin. Simulatin results are included. Key-Wrds: - Quadrature scillatr, Current-mde, Vltage-mde, Current cnveyr, FDCCII. Intrductin A quadrature scillatr is used because the circuit prvides tw sinusids with 9 phase difference, as fr example in telecmmunicatins fr quadrature mixers and single-sideband generatrs r fr measurement purpses in vectr generatrs r selective vltmeters. Therefre, quadrature scillatrs cnstitute an imprtant unit in many cmmunicatin and instrumentatin systems [-6]. Nte that, the quadrature scillatrs in [-] generated vltage-mde signals and the nes in [- 6] generated current-mde signals. Current-mde scillatrs with high utput impedance are f great interest because that make easy t drive lads withut using buffering device [7-9]. On the ther hand, circuits that emply nly grunded capacitrs and resistrs are beneficial frm the pint f view f integrated circuit implementatin [9-]. The previus current-mde quadrature scillatrs presented in [-3] emply flating passive cmpnents and require additinal current fllwers fr sensing and taking ut the quadrature utputs therein and the use f these additinal current fllwers with the virtual grunded input may result in flating capacitrs realizatin fr what is riginally described as grunded capacitrs realizatin. The fully differential secnd-generatin current cnveyr (FDCCII) [] was prpsed t imprve the dynamic range in mixed-mde applicatins where fully differential signal prcessing is required. Because the fully differential f the input vltage signals are cnveyed t the x terminals and the x terminals current signals are cnveyed t the z terminals in FDCCII. The applicatins f FDCCIIs in filters and scillatrs design ften using nly grunded passive cmpnents and were demnstrated in [-4]. The use f nly grunded capacitrs and resistrs is ideal fr integrated circuit implementatin [9-]. Sme applicatins f FDCCIIs in the designs f fully differential secndrder filters and vltage-mde universal secndrder filters were als presented in [5-6]. In, Chang et al. prpsed a current-mde sinusidal scillatr with high utput impedance using ne FDCCII, tw grunded capacitrs and three grunded resistrs [3]. In 6, Hrng et al. prpsed tw quadrature scillatr circuits [7]. Each scillatr circuit in [7] uses ne FDCCII, tw grunded capacitrs and tw/three resistr. The current-mde quadrature utput signals can be btained in the first circuit. The current-mde and vltage-mde quadrature utput signals can be btained, simultaneusly, in the secnd circuit. Hwever, the design f FDCCII based quadrature scillatrs has nt been studied sufficiently. In this paper, anther tw new current-mde quadrature scillatr circuits each using nly ne ISSN: Issue 3, Vlume 7, March 8

2 WSEAS TRANSACTIONS n CIRCUITS AND SYSTEMS Jiun-Wei Hrng, Chun-Li Hu, Chun-Ming Chang, FDCCII, tw grunded capacitrs and tw grunded resistrs are presented. Each f the prpsed circuit exhibits tw high utput impedance sinusidal currents with 9 phase difference. The scillatin cnditins and scillatin frequencies f the prpsed circuits are rthgnal cntrllable. Althugh the prpsed circuits using mre cmplicated active cmpnents (FDCCIIs) with respect t the previus current-mde quadrature scillatrs in [-3], the prpsed circuits having the advantages f emplying nly grunded passive cmpnents; high utput impedance current signals withut using additinal current fllwers and the scillatin cnditins and scillatin frequencies can be rthgnal cntrllable thrugh grunded passive cmpnents. With respect t the high utput impedance current-mde quadrature scillatrs in [4-6], the current-mde and vltage-mde quadrature signals can be simultaneusly btained in the secnd prpsed circuit. With respect t the high utput impedance current-mde sinusidal scillatrs in [3], high utput impedance quadrature current signals can be btained in the prpsed circuits and emplying less resistrs. Mrever, the vltagemde quadrature signals can be simultaneusly btained in the secnd prpsed circuit. With respect t the FDCCIIs based quadrature scillatrs in [7], tw new quadrature scillatr circuits are presented in this paper. Prpsed Circuits The FDCCII is defined by the equatins []: iy iy iy iy v v i i 3 4 xa xb zai zbi = ± ± v v v v i i v v y y y3 y4 xa xb zai zbj () The first prpsed quadrature scillatr is shwn in Fig.. The characteristic equatin f the circuit can be expressed as s C C + sg (C C ) + G G = () Fig. The first prpsed quadrature scillatr. C = C (3) ω = CC RR (4) Frm equatins (3) and (4), the scillatin cnditin and scillatin frequency can be rthgnal adjustable. Frm Fig., under steady state, the relatinships between utput currents I ut and I ut are I ut = C ωc R y y y 3 y 4 x a +z a (FDCCII) x b +z a +z +z +z b a3 b R I ut j e 9 I ut I ut (5) ensuring the currents I ut and I ut t be in quadrature. I ut y +z a y y 3 y 4 +z b -z b +z a (FDCCII) x b R x a +z b3 Fig. The secnd prpsed quadrature scillatr. R C V V C +z b4 R C I ut The scillatin cnditin and scillatin frequency can be btained as ISSN: Issue 3, Vlume 7, March 8

3 WSEAS TRANSACTIONS n CIRCUITS AND SYSTEMS Jiun-Wei Hrng, Chun-Li Hu, Chun-Ming Chang, The secnd prpsed quadrature scillatr is shwn in Fig.. The characteristic equatin f the circuit can be expressed as s C C + sc (G G ) + G G = (6) The scillatin cnditin and scillatin frequency can be btained as R = R (7) ω = C C R R (8) Frm equatins (7) and (8), the scillatin cnditin and scillatin frequency can be rthgnal adjustable. Frm Fig., under steady state, the relatinships between utput vltages V and V are V = ωc R j e 9 V (9) ensuring the vltages V and V t be in quadrature. The relatinships between utput currents I ut and I ut are I ut = ωc R j e 9 I ut () ensuring the currents I ut and I ut t be in quadrature. The prpsed quadrature scillatr circuits emply nly grunded capacitrs and resistrs. The use f grunded capacitrs and resistrs is particularly attractive fr integrated circuit implementatin [9- ]. Because the utput impedances f the currents I ut and I ut in Fig. - are very high, the tw utput terminals, I ut and I ut, can be directly cnnected t the next stage. The current-mde and vltage-mde quadrature signals can be simultaneusly btained frm Fig.. Frm equatins (5), (9) and (), the magnitudes f the quadrature signals are nt the same. Fr the applicatins needing equal magnitude quadrature utputs, ther amplifying circuits are needed. 3 Nn-Ideal Effects Taking the nn-idealities f the FDCCII int accunt, the relatinship f the terminal vltages and currents can be rewritten as: v xa = αa v y - αa v y + α a3 v y3, v xb = -αb v y + αb v y + αb4 v y4, i y = i y = i y3 = i y4 =, i zai = ± βai i xa and i zbj = ± βbj i xb, where α ak = - ε avk and ε avk ( ε avk <<) is the vltage tracking errr frm the k-th v y terminal t the v xa terminal f the FDCCII, α bk = - ε bvk and ε bvk ( ε bvk <<) is the vltage tracking errr frm the k-th v y terminal t the v xb terminal f the FDCCII, β ai = - ε ai and ε ai ( ε ai <<) is the utput current tracking errr frm the v xa terminal t the i- th v za terminal f the FDCCII, β bj = - ε bj and ε bj ( ε bj <<) is the utput current tracking errr frm the v xb terminal t the j-th v zb terminal f the FDCCII. The characteristic equatin f Fig. becmes s CC αa βa+ s[ G ( C Cα aβ a) + CG βa βb ( αaα b αa α b)] + G G β α () b b = The mdified scillatin cnditin and scillatin frequency are CRβ aβ b( α aα b α aα b ) C = Cα aβ a R () αb βb ω = (3) C C R R α β a a The active and passive sensitivities f the quadrature scillatr are all lw and btained as S s ω = b β S b α a, a ω α, β = ; S ω C, R = C, R, The characteristic equatin f Fig. becmes C C + sc ( Gα aβ a Gα bβ b ) + G G α α β β (4) a3 b a b = The mdified scillatin cnditin and scillatin frequency are R R α β a a = (5) αbβb ISSN: Issue 3, Vlume 7, March 8

4 WSEAS TRANSACTIONS n CIRCUITS AND SYSTEMS Jiun-Wei Hrng, Chun-Li Hu, Chun-Ming Chang, α α β β a3 b a b ω = (6) CC RR The active and passive sensitivities f the quadrature scillatr are all lw and btained as S ω 3,, = b α a β a β S b C, C, R, ω α, R = 4 Simulatin Results The quadrature scillatrs were simulated using HSPICE. The FDCCII was realized by the CMOS implementatin in Fig. f [] and is shwn in Fig. 3 (using.8 μ m MOSFET frm TSMC). The aspect ratis f the MOS transistrs were chsen as in Table. The multiple current utputs can be easily implemented by adding utput branches. Fig. 4(a) represents the current-mde quadrature sinusidal utput wavefrms f Fig. with C = 45pF, C = 47pF, R = k Ω, R = k Ω, V bp = V, V bn = V, I B =.ma, I SB =.ma and the pwer supply ±.5V where C was designed t be larger then C t ensure the scillatins will start. The pwer dissipatin is mW. Fig. 4(b) shws the simulated frequency spectrum f I ut and I ut in Fig.. The results f the I ut ttal harmnic distrtin analysis are summarized in Table. Fig. 5(a) and (b) represents the current-mde quadrature sinusidal utput wavefrms and spectrums f Fig. with C = 45pF, C = 45pF, R = k Ω, R =.9k Ω where R was designed t be larger then R t ensure the scillatins will start. Fig. 5(c) and (d) represents the vltage-mde quadrature sinusidal utput wavefrms and spectrums f Fig.. The pwer dissipatin is 8.935mW. The results f the V ttal harmnic distrtin analysis are summarized in Table 3. 5 Cnclusin In this paper, tw new quadrature scillatrs each using ne FDCCII, tw grunded capacitrs and tw grunded resistrs are prpsed. The scillatin cnditins and scillatin frequencies f the prpsed quadrature scillatrs have the advantage f being rthgnal cntrllable. Tw high utput impedance sinusid currents with 9 phase difference are available in each circuit cnfiguratin. The use f nly grunded capacitrs and resistrs makes the prpsed circuits ideal fr integrated circuit implementatin. The current-mde and vltage-mde quadrature signals can be simultaneusly btained in the secnd prpsed circuit. References: [] A. S. Sedra and K. C. Smith, Micrelectrnic circuits, furth editin, Oxfrd University Press, Inc., 998. [] I. A. Khan and S. Khwaja, An integrable gm-c quadrature scillatr, Internatinal Jurnal f Electrnics, Vl.87,, pp [3] R. Hlzel, A simple wide-band sine wave quadrature scillatr, IEEE Transactins n Instrumentatin and Measurement, Vl.4, 993, pp [4] M. T. Ahmed, I. A. Khan and N. Minhaj, On transcnductance-c quadrature scillatrs, Internatinal Jurnal f Electrnics, Vl.83, 997, pp. -7. [5] A. M. Sliman, Synthesis f grunded capacitr and grunded resistr scillatrs, Jurnal f the Franklin Institute, Vl.336, 999, pp [6] J. W. Hrng, Current differencing buffered amplifiers based single resistance cntrlled quadrature scillatr emplying grunded capacitrs, IEICE Transactins n Fundamentals f Electrnics, Cmmunicatins and Cmputer Sciences, Vl.E85-A,, pp [7] P. Prmmee and K. Dejhan, An integrable electrnic-cntrlled quadrature sinusidal scillatr using CMOS peratinal transcnductance amplifier, Internatinal Jurnal f Electrnics, Vl.89,, pp [8] J. W. Hrng, C. L. Hu, C. M. Chang, W. Y. Chung, H. W. Tang and Y. H. Wen, Quadrature scillatrs using CCIIs, Internatinal Jurnal f Electrnics, Vl.9, 5, pp. -3. [9] J. W. Hrng, Current cnveyrs based allpass filters and quadrature scillatrs emplying grunded capacitrs and resistrs, Cmputers and Electrical Engineering, Vl.3, 5, pp [] J. W. Hrng, C. L. Hu, C. M. Chang, S. W. Pan, J. Y. Shie and Y. H. Wen, Third-rder quadrature scillatr with grunded capacitrs using CCIIs, WSEAS Transactins n Electrnics, Vl.4, 7, pp. -. [] J. J. Chen, C. C. Chen, H. W. Tsa and S. I. Liu, Current-mde scillatrs using single current fllwer, Electrnics Letters, Vl.7, 99, pp [] M. T. Abuelma atti, Grunded capacitr current-mde scillatr using single current fllwer, IEEE Transactins n Circuits and Systems-I: Fundamental Thery and Applicatins, Vl.39, 99, pp. 8-. ISSN: Issue 3, Vlume 7, March 8

5 WSEAS TRANSACTIONS n CIRCUITS AND SYSTEMS [3] M. T. Abuelma atti and H. A. Alzaher, Cmment n Current-mde quadrature sinusidal scillatr using single FTFN, Internatinal Jurnal f Electrnics, Vl.85, 998, pp [4] S. Minaei and O. Cicekglu, New current-mde integratr, all-pass sectin and quadrature scillatr using nly active elements, st IEEE Internatinal Cnference n Circuits and Systems fr Cmmunicatins, Vl.6-8,, pp [5] J. W. Hrng, Current-mde quadrature scillatr with grunded capacitrs and resistrs using tw DVCCs, IEICE Transactins n Fundamentals f Electrnics, Cmmunicatins and Cmputer Sciences, Vl.E86-A, 3, pp [6] S. Maheshwari and I. A. Khan, Current cntrlled third rder quadrature Oscillatr, IEE Prceedings: Circuits, Devices and Systems, Vl.5, 5, pp [7] M. T. Abuelma atti and H. A. Al-Zaher, Current-mde sinusidal scillatrs using single FTFN, IEEE Transactins n Circuits and Systems- II: Analg and Digital Signal Prcessing, Vl.46, 999, pp [8] U. Cam, A. Tker, O. Cicekglu and H. Kuntman, Current-mde high utput impedance sinusidal scillatr cnfiguratin emplying single FTFN, Analg Integrated Circuits and Signal Prcessing, Vl.4,, pp [9] S. S. Gupta and S. Senani, Realisatin f current-mde SRCOs using all grunded passive elements, Frequenz, Vl.57, 3, pp [] M. T. Abuelma atti and A. A. Al-Ghumaiz, Nvel CCI-based single-element-cntrlled scillatrs emplying grunded resistrs and Jiun-Wei Hrng, Chun-Li Hu, Chun-Ming Chang, capacitrs, IEEE Transactins n Circuits and Systems-I: Fundamental Thery and Applicatins, Vl.43, 996, pp [] M. Bhusan and R. W. Newcmb, Grunding f capacitrs in integrated circuits, Electrnic Letters, Vl.3, 967, pp [] A. A. El-Adawy, A. M. Sliman and H. O. Elwan, A nvel fully differential current cnveyr and applicatins fr analg VLSI, IEEE Transactins n Circuits and Systems-II: Analg and Digital Signal Prcessing, Vl.47,, pp [3] C. M. Chang, B. M. Al-Hashimi, H. P. Chen, S. H. Tu and J. A. Wan, Current-mde single resistance cntrlled scillatrs using nly grunded passive cmpnents, Electrnics Letters, Vl.38,, pp [4] C. M. Chang, B. M. Al-Hashimi, C. L. Wang and C. W. Hung, Single fully differential current cnveyr biquad filters, IEE Prceedings: Circuits, Devices and Systems, Vl.5, 3, pp [5] S. M. Al-Shahrani, Fully differential secndrder filter, The 47 th IEEE Internatinal Midwest Sympsium n Circuits and Systems, Vl.3, 4, pp. III99-III3. [6] C. M. Chang and H. P. Chen, Single FDCCIIbased tunable universal vltage-mde filter, Circuits, Systems, and Signal Prcessing, Vl.4, 5, pp. -7. [7] J. W. Hrng, C. L. Hu, C. M. Chang, H. P. Chu, C. T. Lin and Y. H. Wen, Quadrature scillatrs with grunded capacitrs and resistrs using FDCCIIs, ETRI Jurnal, Vl.8, 6, pp ISSN: Issue 3, Vlume 7, March 8

6 WSEAS TRANSACTIONS n CIRCUITS AND SYSTEMS Jiun-Wei Hrng, Chun-Li Hu, Chun-Ming Chang, Table Aspect ratis f the MOS in Fig. 3. MOS transistrs Aspect rati (W/L) M -M 6 6/4.8 M 7, M 8, M 9, M 3 48/4.8 M, M, M, M 4 /4.8 M 4, M 5, M 8, M 9, M 5, M 9, M 3, M 33, M 34, 4/.4 M 37, M 38, M 4, M 4, M 45, M 46, M 49, M 5, M 53, M 54, M 57, M 58 M 6, M 7, M, M, M 6, M 3, M 3, M 35, M 36, M 39, M 4, M 43, M 44, M 47, M 48, M 5, M 5, M 55, 6/.4 M 56, M 59, M 6 M, M 3, M 7, M 8 4.8/4.8 Table Ttal harmnic distrtin analysis f I ut in Fig.. Harmnic Frequency fft_mag fft_mag fft_phase Number (hz) (db) (deg).65m u M n M n M n M n M n dc cmpnent: mag(db)= -.E+ ttal harmnic distrtin = m percent ISSN: Issue 3, Vlume 7, March 8

7 WSEAS TRANSACTIONS n CIRCUITS AND SYSTEMS Jiun-Wei Hrng, Chun-Li Hu, Chun-Ming Chang, Table 3 Ttal harmnic distrtin analysis f V in Fig.. Harmnic Frequency fft_mag fft_mag fft_phase Number (hz) (db) (deg).75m m M m M m M u M u dc cmpnent: mag(db)= E+ ttal harmnic distrtin =.475 percent ISSN: Issue 3, Vlume 7, March 8

8 WSEAS TRANSACTIONS n CIRCUITS AND SYSTEMS Jiun-Wei Hrng, Chun-Li Hu, Chun-Ming Chang, Fig. 3 The implementatin f FDCCII. ISSN: Issue 3, Vlume 7, March 8

9 WSEAS TRANSACTIONS n CIRCUITS AND SYSTEMS Jiun-Wei Hrng, Chun-Li Hu, Chun-Ming Chang, I ut I ut (a) I ut I ut (b) Fig. 4 (a) The simulated current-mde quadrature utput wavefrms f Fig.. (b) The simulated frequency spectrum f I ut and I ut in Fig.. I ut I ut (a) ISSN: Issue 3, Vlume 7, March 8

10 WSEAS TRANSACTIONS n CIRCUITS AND SYSTEMS Jiun-Wei Hrng, Chun-Li Hu, Chun-Ming Chang, I ut I ut (b) V V (c) V V Fig. 5 (a) The simulated current-mde quadrature utput wavefrms f Fig.. (b) The simulated frequency spectrum f I ut and I ut in Fig.. (c) The simulated vltage-mde quadrature utput wavefrms f Fig.. (d) The simulated frequency spectrum f V and V in Fig.. (d) ISSN: Issue 3, Vlume 7, March 8