CMOS akım taşıyıcılarının makromodellerinin oluşturulması ve akım taşıyıcılı sistemlerin analizi
Formation of macromodels of CMOS current conveyorsand analysis of current conveyors filters
- Tez No: 46583
- Danışmanlar: PROF.DR. HAKAN KUNTMAN
- Tez Türü: Yüksek Lisans
- Konular: Elektrik ve Elektronik Mühendisliği, Electrical and Electronics Engineering
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 1995
- Dil: Türkçe
- Üniversite: İstanbul Teknik Üniversitesi
- Enstitü: Fen Bilimleri Enstitüsü
- Ana Bilim Dalı: Belirtilmemiş.
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: 94
Özet
ÖZET Akım taşıyıcı, genel olarak, akımın çok farklı empedans seviye leri arasında taşındığı aktif bir üç-uçlu devredir. Giriş-çıkış bü yüklükleri akım olduğundan, gerilim modunda çalışan işlemsel kuvvet lendiricilere oranla daha yüksek kesim frekansına sahiptirler. Bu ö- devde, önce dört adet akım taşıyıcı devresi incelenmiştir. Analiz yapılırken, doğrusallık aralığı ve kesim frekansı ölçüt olarak alın mış ve incelemel-er sonunda 2. akım taşıyıcının doğrusallık aralığı çok dar bulunarak daha ileriki incelemelerde kullanılmamıştır. Geri ye kalan üç devre için uç karakteristiklerinden yararlanılarak makro- modeller oluşturulmuştur. Bu makromodel 1 erden yararlanılarak yüksek dereceden süzgeçlerin PSpice simülasyonları yürütülebilmiştir. İkin ci dereceden süzgeçlerin analizi ise hem akım taşıyıcılar, hem de makromodel 1 eriyle yürütülmüş ve sonuçların uyumluluğu ve analiz süre sinin kullanılan devreye (akım taşıyıcı ya da makromodel i > göre nasıl değiştiği araştırılmıştır. Sonuçta, aradaki uyumun yeterli ol duğu, simülasyonda makromodel kul 1 anman ınsa, özellikle büyük devre lerde simülasyon süresi açısından oldukça kazanç sağladığı görülmüş tür. Ayrıca, bu yolla yakınsayamama, bellek yetersizliği gibi sorun larla karşılaşıl madiği da anlaşılmıştır. iv
Özet (Çeviri)
SUMMARY Format i cm of Hacromodels of CMOS Current Conveyors and Analysis of Current Conveyor Filters Though electrical engineers, worked with voltage-mode for years, it is more advantageous to utilize current -activated circuits in electronics. The reason is that, the impedance level in current- mode circuits is low, which results in the reducing of the time constants (and thus the frequency limitations), caused by the parasitic capasitances. Utilizing these ideas, the first current conveyor CCI was introduced by Smith and Sedra in 1968, after when came the second- generation current conveyor, CCI I (in 1970, from Smith and Sedra), whose performance was much better than that of CCI. Since then, the current conveyor (especially CCI I) has become one of the basic building blocks used in general purpose analog circuit structures. Many types of active networks (for example, oscillators and particularly filters) can be realized by utilizing the current conveyor as the active device. Due to the improvements in the CMOS technology, which enables complicated chips to be manufactured, analog functional CMOS blocks ( current conveyor is one of them) are frequently being worked on. In this work, four separate CMOS current conveyors were analyzed end their performances were inspected. The current conveyors were used to design filter networks and the designed filters were analyzed with the circuit simulation program PSpice. High order filters were found difficult to simulate because of the largeness of the circuits, causing convergence and memory problems. Macro-models of each current conveyor were extracted and they were used in place of the current conveyors in simulation, to overcome the problems above. Second order filters were analyzed by using the current conveyors and their macromodels separately and the results - vwere wittnessed to be in agreement with each other. It was also observed that, besides giving the same results as the circuits simulateed with current conveyors, the simulation time of the circuits analyzed with macromodels were obviously shorter. A current conveyor (CCII) is a three-terminal active network, namely X, Y and Z terminals. For the ideal case, the Y input current is zero and the X input voltage vK is equal to the Y input voltage vy. Finally, the output current ie of terminal Z is equal to either iM or -i«, depending on the type of the current conveyor (i.e. positive or negative: CCII* or CCII-). The analyzed current conveyor structures, in reality, can be turned from a CCII“”“ into a CCII-, and vise versa, with some additions. Therefore, the actual number of current conveyors analyzed in this work is eight (four couples). Frequency and DC performances of the current conveyors were inspected and the bandwidths and input linearity ranges of each were determined. One of the current conveyors were observed to possess a very narrow linearity range and it was eliminated because of this drawback. The remainig three current conveyors were used to build second and higher order filters and their analyses were tried to be carried out with PSpice. The second-order filters were, usually, easy to simulate with current conveyors. However, high-order filters caused convergence and memory problems during simulations, which blocked the analyses. The reason was the large number of the transistors in the analyzed circuit, obstructing the convergence of the numerical calculations or filling up the memory before the calculations were completed. So as to overcome those problems, macrorrodels of each current conveyor* were extracted, whose terminals were expected to show the same electrical characteristics as the current conveyors. Trie parameters of the macromodels were extracted by anal yzing the input and the output characteristics ( frequency and DC analyses ) of each current conveyor. As a result, the general form of the current conveyor macromodel circuit is obtained (See Figure 1). The values of each device in the macromodel circuit can analytically and graphically be determined by examining the terminal arid inter-terminal frequency and DC curves of the actual current conveyors. VIThe extracted macromodel form was used to simulate high-order filter networks and the results of the frequency and transient analyses were found to be similar to the expected results. The non- ideality effects of the current conveyors which would probably be encountered if the simulations had successfully been carried out with the current conveyors, were observed to show theirselves in the results. This was one of the evidences of the adequate representation of the current conveyors by the corresponding macromodel s. e1=v(ry) Figure 1. General circuit form of the extracted current conveyor macromodel - VI 1Table 1. Comparison of simulation times of the 2”'=' order filters with current conveyors and macromodels. VI 11The second evidence showed itself after the simulation of second-order filters with current conveyors and their corresponding macromodels, separately. When the results were compared, they were wittnessed to be in close agreement, proving the adequate representation of each current conveyor by it corresponding macromodel. Another point was that, the simulation time was obviously shorter for tha analyses carried out with the macromodels, than the ones carried out with the current conveyors. The comparison of simulation times are made on Table 1. The results show that it is wiser to utilize macromodels instead of current conveyors when simulation of large networks containing current conveyors is the case, since the obtained results will resemble those expected from a simulation of the same network with current conveyors and no convergence or memory problems will be encountered, with the simulation time shortened in addition. IX
Benzer Tezler
- Kontrollü akım taşıyıcılarda performans iyileştirme çalışması
A Study of performance evaluation in controlled current conveyor
DENİZ Y. KAYMAK
Yüksek Lisans
Türkçe
2001
Elektrik ve Elektronik Mühendisliğiİstanbul Teknik ÜniversitesiPROF. DR. HAKAN KUNTMEN
- Akım taşıyıcıları kullanarak aktif devre sentezinde yeni olanaklar
Başlık çevirisi yok
HERMAN SEDEF
Doktora
Türkçe
1994
Elektrik ve Elektronik MühendisliğiYıldız Teknik ÜniversitesiElektronik ve Haberleşme Mühendisliği Ana Bilim Dalı
PROF. DR. SEZGİN ALSAN
- Akım taşıyıcılar kullanarak filtre devreleriin VLSI tasarımı ve gerçeklenmesi
Başlık çevirisi yok
HÜLYA DAMGACI
Yüksek Lisans
Türkçe
1996
Elektrik ve Elektronik MühendisliğiYıldız Teknik ÜniversitesiElektrik-Elektronik Mühendisliği Ana Bilim Dalı
PROF. DR. ATİLLA ATAMAN
- İkinci kuşak eviren akım taşıyıcılarla tasarlanan osilatörler
New RC sinusoidal oscilators employing inverting second generation current conveyors
MEHMET DİŞÇİGİL
Yüksek Lisans
Türkçe
2000
Elektrik ve Elektronik Mühendisliğiİstanbul Teknik ÜniversitesiPROF.DR. HAKAN KUNTMAN
- 0.18um teknolojısınde birinci ve üçüncü kuşak akım taşıyıcılar ıle yeni olanaklar
New possibilities with first and third generation current conveyors in 0.18μm technology
OĞUZ GONCA
Yüksek Lisans
Türkçe
2014
Elektrik ve Elektronik Mühendisliğiİstanbul Teknik ÜniversitesiElektronik ve Haberleşme Mühendisliği Ana Bilim Dalı
PROF. DR. HULUSİHAKAN KUNTMAN