Third-Order Voltage-Mode Quadratrue Oscillator Using DDCC and OTAs

Transcription

1 20 nternational Conference on Circuit, Sytem and Simulation PCST vol.7 (20) (20) ACST Pre, Singapore Third-Order oltage-mode Quadratrue Ocillator Uing and Adiorn Kwawibam, Bancha Sreewirote 2 and Winai Jaikla 3 College of ntegrated Science and Technology, Rajamangala Univerity of Technology Lanna 2 Department of Electrical Engineering, Faculty of Engineering, Thonburi Univerity 3 Department of Electronic Technology, Faculty of ndutrial Technology, Suan Sunandha Rajabhat Univerity Abtract. Thi article preent a 3 rd voltage-mode quadrature illator uing differential different current conveyor () and operational tranconductance amplifier () a active element. The propoed circuit i realized from a non-inverting lole integrator and an inverting econd order low-pa filter. The illation condition and illation frequency can be electronically/orthogonally controlled via input bia current. The circuit decription i very imple, coniting of merely, 2, grounded reitor and 2 grounded capacitor. Uing only grounded element, the propoed circuit i then uitable for C architecture. The PSPCE imulation reult are depicted, and the given reult agree well with the theoretical anticipation. The power conumption i approximately.86mw at ±.25 upply voltage. Keyword: Ocillator,,. ntroduction An illator i an important baic building block, which i frequently employed in electrical engineering application. Among the everal kind of illator, a quadrature illator i widely ued becaue it can offer inuoidal ignal with 90 phae difference, for example, in telecommunication for quadrature mixer and ingle-ideband []. Several implementation of econd order quadrature illator uing different high-performance active building block, uch a, [2], current conveyor [3], four-terminal floating nullor (FTFN) [4-5], current follower [6], current differencing buffered amplifier (CDBA) [7], current differencing tranconductance amplifier (CDTA) [8], fully-differential econd-generation current conveyor (FDCC) [9], and differencing voltage current conveyor (DCC) [0], have been reported. Recently, it ha been proved that the third order illator provide good characteritic with lower ditortion than econd order illator [-2]. From our literature found that the third order illator employing CCC [], [2-3], CDTA [4], have been propoed. The aim of thi paper i to propoe a third order voltage-mode illator, baed on and. The feature of the propoed circuit are that: the illation condition can be adjuted independently from the illation frequency by electronic method. The circuit contruction conit of, 2, grounded reitor and 2 grounded capacitor. The PSPCE imulation reult are alo hown, which are in correpondence with the theoretical analyi. 2. Circuit Principle 2.. Baic concept of Correponding author. Tel.: ; fax: addre: Winai.ja@hotmail.com. 37

2 The electrical behavior of the ideal are repreented by the following hybrid matrix [5]: Y Y Y2 = Y2. () Y3 Y The ymbol and the equivalent circuit of the are illutrated in Fig. and, repectively. Y Y Y Y2 = Y = 0 Y z = 0 Y = 0 Y Y Y2 Y3 = Fig. : Symbol Equivalent circuit Baic concept of An ideal operational tranconductance amplifier () ha infinite input and output impedance. The output current of an i given by ( ) O = gm, (2) where g m i the tranconductance of the. Thi gm can be tuned by external input bia current ( B ). For a CMOS, the tranconductance can be expreed a W gm = kb; k = μncox L. (3) Here k i the phyical tranconductance parameter of the MOS tranitor. The ymbol and the equivalent circuit of the are illutrated in Fig. 2 and, repectively. B O in Fig. 2: Symbol Equivalent circuit General tructure of 3 rd illator The illator i deigned by cacading an inverting econd order low-pa filter and the lole integrator a ytematically hown in Fig. 3 [3]. From block diagram in Fig. 3, we will receive the characteritic equation a R i g m in R o O 3 2 b a ck = 0. (4) k c 2 b a Fig. 3: mplementation block diagram for the 3 rd illator. From Eq. (4), the illation condition (OC) and illation frequency (ω ) can be written a 38

3 OC : ab = ck and ω = a. (5) From Eq. (5), if a = c, the illation condition and illation frequency can be adjuted independently, which are the illation condition can be controlled by k and b, while the illation frequency can be tuned by a Propoed 3 rd voltage-mode quadrature illator A mentioned in lat ection, the propoed illator i baed on the inverting econd order low-pa filter and the lole integrator. n thi ection, thee circuit will be decribed. The inverting econd order low-pa filter baed on and i hown in Fig. 4. The voltage tranfer function of thi circuit can be written a T() LP LP = = in gm CC 2R g 2 m CR CCR 2. (6) From Eq. (6), the parameter ab, and c can be expreed a g m a = c = and CC R 2 b =. (7) CR Fig. 4 how the lole integrator uing. Conidering the circuit in Fig. 4 and uing propertie, we will receive O in k =, where k=g m2 /C 3. (8) in Y R C B LP C2 in B2 O C 3 Fig. 4: nverting econd order low-pa filter Lole integrator. The completed 3 rd voltage-mode quadrature illator i hown in Fig. 5. The illation condition (OC) and illation frequency (ω ) can be written a gm2 gm = and ω =. (9) CR C CC R 3 2 f gm = k B, gm2 = k 2 B2 and C = C2 = C3 = C, the illation condition and illation frequency can be rewritten a k 2 B 2 R = and ( ) k 2 B ω = C R. (0) t i obviouly found that, from Eq. (0), the illation condition and illation frequency can be adjuted independently, which are the illation condition can be controlled by etting R and B2, while the illation frequency can be tuned by etting B. From the circuit in Fig. 5, the voltage tranfer function from o to o2 i 39

4 o2() gm2 =. () () C o 3 For inuoidal teady tate, Eq. () become ( jω) g o2 m2 j90 = e. (2) ( jω) ωc o 3 The phae difference φ between o and o2 i φ = -90 enuring that the voltage o2 and o are in quadrature. Y R C B o C 2 B2 o2 C 3 3. Simulation Reult Fig. 5: Propoed 3 rd quadrature illator. To invetigate the theoretical analyi, the propoed filter in Fig. 5 i imulated by uing the PSPCE imulation program. nternal contruction of and ued in imulation are repectively hown in Fig. 6 and. The PMOS and NMOS tranitor have been imulated by repectively uing the parameter of a 0.25µm TSMC CMOS technology [6]. The tranitor apect ratio of PMOS and NMOS tranitor are indicated in Table. The circuit wa biaed with ±.25 upply voltage, BB =-0.6, C =C 2 = C 3 =0.nF, B =65µA, B2 =70µA and R=0.75kΩ. Thi yield imulated illation frequency of.69mhz. Fig. 7 how imulated quadrature output waveform. Fig. 7 how the imulated output pectrum, where the total harmonic ditortion (THD) i about.75%. The power conumption i approximately.86mw. Fig. 6: nternal contruction of. TABLE. DMENSONS OF THE TRANSSTORS Tranitor W (µm) L (µm) M -M 4, M 9 -M M 5 -M M 9 -M M -M M M 7 -M

5 50 00m o2 o 0m THD=.75% f=.69mhz 0 00µ Time (µ) 4. Concluion 0µ Frequency (MHz) Fig. 7: Output voltage waveform Spectrum. A 3 rd voltage-mode quadrature illator baed on and ha been preented. The feature of the propoed circuit are that: illation frequency an illation condition can be orthogonally adjuted via input bia current; it conit of, 2, grounded reitor and 2 grounded capacitor, which i convenient to fabricate. The PSPCE imulation reult agree well with the theoretical anticipation. 5. Reference []. A. Khan and S. Khawaja, An integrable gm-c quadrature illator. nt. J. Electronic, 2000, 87(): [2] K. Kumwachara and W. Surakampontorn, An integrable temperature-inenitive gm RC quadrature illator. nternational Journal of Electronic, 2003, 90(): [3] M. T. Abuelma atti and A. A. Al-Ghumaiz, Novel CC-baed ingle-element-controlled illator employing grounded reitor and capacitor. EEE Tranaction on Circuit and Sytem-, 996, 43: [4] M. T. Abuelma atti and H. A. Al-aher, Current-mode inuoidal illator uing ingle FTFN. EEE Tranaction on Circuit and Sytem-, 999: 46, [5] U. Cam, A. Toker, O. Cicekoglu, and Kuntman, Current-mode high output impedance inuoidal illator configuration employing ingle FTFN. Analog ntegrated Circuit and Signal Proceing, 2000, 24: [6] M. T. Abuelma atti, Grounded capacitor current-mode illator uing ingle current follower. EEE Tranaction Circuit and Sytem-, 992, 39: [7] R. Nandi, P. enkatewaran, Soumik Da and M. Kar, CDBA-baed electronically tunable filter and inuoid quadrature illator. Journal of Telecommunication, 200, 4(): [8] A. Lahiri, New current-mode quadrature illator uing CDTA. ECE Electronic Expre, 2009, 6(3): [9] J. W. Horng, C. L. Hou, C. M. Chang, H. P. Chou, C. T. Lin, and Y. H. Wen, Quadrature illator with grounded capacitor and reitor uing FDCC. ETR Journal, 2006, 28: [0] J. W. Horng, Current-mode quadrature illator with grounded capacitor and reitor uing two DCC. ECE Tranaction Fundamental of Electronic, Communication and Computer Science, 2003, E86-A: [] S. Mahehwari, and. A. Khan, Current controlled third-order quadrature illator. EE Proceeding on Circuit Device Sytem, 2005, 52: [2] P. Prommee, K. Dejhan, An integrable electronic-controlled quadrature inuoidal illator uing CMOS operational tranconductance amplifier. nternational Journal of Electronic, 2002, 89: [3] T. Tukutani, Y. Sumi, and Y. Fukui, Electronically controlled current-mode illator uing MO- and grounded capacitor. Frequenz, 2006, 60: [4] J. W. Horng, Current-mode third-order quadrature illator uing CDTA, Active and Paive Electronic Component, 2009, Article D 7897, doi:0.55/2009/7897. [5] W. Chiu, S.. Liu, H. W. Tao and J. J. Chen, COMS differential difference current conveyor and their application. EE Proceeding Circuit Device and Sytem, 996, 43: [6] P. Prommee, K. Angkeaw, M. Somdunyakanok, K. Dejhan. CMOS-baed near zero-offet multiple input max min circuit and it application. Analog ntegr. Circuit Signal Proce, 2009, 6: