INVERTING CURRENT FEEDBACK OPERATIONAL AMPLIFIER AND ITS APPLICATIONS TO MOS-C CIRCUIT REALIZATION

Bu çalışmada, terslenmiş akım geri beslemeli işlemsel yükselteç (TAGBİY) olarak isimlendirilen bir aktif eleman tanıtılmıştır. TAGBİY'in CMOS gerçeklemeleri verilmiştir. Bu yapı bloğunun, devrelerin MOS-C gerçeklemeleri için çok uygun olduğu gösterilmiştir. Uygulama örnekleri olarak TAGBİY kullanan Tow-Thomas ve Kerwin-Huelsman-Newcomb süzgeçleri ile birinci dereceden tüm geçiren süzgeç ve salıngaç devreleri sunulmuştur. Teorik analizler PSPICE benzetim sonuçları ile doğrulanmıştır. In this paper, an active element called inverting current feedback operational amplifier (ICFOA) is described. CMOS implementations of ICFOA are included. It has been shown that this building block is very suitable for MOS-C realization of circuits. As the application examples, MOS-C implementation of Tow-Thomas biquad, Kerwin-Huelsman-Newcomb biquad, first order allpass filter and quadrature oscillator using ICFOA are presented. Theoretical analysis is verified by PSPICE simulations

The frequency of Duchenne muscular dystrophy/Becker muscular dystrophy and Pompe disease in children with isolated transaminase elevation: results from the observational VICTORIA study

IntroductionElevated transaminases and/or creatine phosphokinase can indicate underlying muscle disease. Therefore, this study aims to determine the frequency of Duchenne muscular dystrophy/Becker muscular dystrophy (DMD/BMD) in male children and Pompe disease (PD) in male and female children with isolated hypertransaminasemia.MethodsThis multi-center, prospective study enrolled patients aged 3–216 months with serum alanine transaminase (ALT) and/or aspartate transaminase (AST) levels >2× the upper limit of normal (ULN) for ≥3 months. Patients with a known history of liver or muscle disease or physical examination findings suggestive of liver disease were excluded. Patients were screened for creatinine phosphokinase (CPK) levels, and molecular genetic tests for DMD/BMD in male patients and enzyme analysis for PD in male and female patients with elevated CPK levels were performed. Genetic analyses confirmed PD. Demographic, clinical, and laboratory characteristics of the patients were analyzed.ResultsOverall, 589 patients [66.8% male, mean age of 63.4 months (standard deviation: 60.5)] were included. In total, 251 patients (188 male and 63 female) had CPK levels above the ULN. Of the patients assessed, 47% (85/182) of male patients were diagnosed with DMD/BMD and 1% (3/228) of male and female patients were diagnosed with PD. The median ALT, AST, and CPK levels were statistically significantly higher, and the questioned neurological symptoms and previously unnoticed examination findings were more common in DMD/BMD patients than those without DMD/BMD or PD (p < 0.001).DiscussionQuestioning neurological symptoms, conducting a complete physical examination, and testing for CPK levels in patients with isolated hypertransaminasemia will prevent costly and time-consuming investigations for liver diseases and will lead to the diagnosis of occult neuromuscular diseases. Trial RegistrationClinicaltrials.gov NCT04120168

Yüksek Performansli Cmos Ftfn Tasarimi Ve Uygulamalari

Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2000Thesis (Ph.D.) -- İstanbul Technical University, Institute of Science and Technology, 2000Akım-modlu devrelerin tasarımına olan ilgi son yıllarda giderek artmaktadır. Bu ilginin başlıca nedenleri, akım-modlu devrelerin gerilim-modlu devrelere göre yüksek band genişliği, düşük güç tüketimi, yüksek dinamik aralık, yüksek yükselme eğimi gibi özelliklere sahip olmasıdır. Bu yüzden çok sayıda akım-çıkışlı aktif devre bloku ve bunların uygulamalarını içeren çalışmalar yapılmıştır. Bu elemanların nullor eşdeğerleri incelendiğinde, en kullanışlı ve esnek aktif yapı bloğunun ideal nullorun gerçeklenmesi olan dört uçlu yüzen nullor (FTFN) olduğu yapılan çalışmalarla gösterilmiştir. FTFN literatürde ya OP-AMP ve akım aynalarından oluşan besleme akımım algılama tekniğini kullanarak ya da iki akım taşıyıcının paralel bağlanmasıyla gerçeklenmektedir. Tümdevre tasarımında düşük güç tüketimi ve yoğun tümleştirme faydalarından dolayı yaygın olarak kullanılan teknoloji CMOS teknolojisidir. Bu tezde, dört adet yeni CMOS FTFN devresi önerilmiştir. Önerilen ilk iki devre literatürdeki uygun akım taşıyıcı (CCII) yapılan kullanılarak türetilmiştir. Üçüncü devre, yüksek kazançlı giriş katma, yüzen çıkış katı olarak adlandırılan ve girişine bağlanan gerilimden birbirinin eviriği iki akım üreten devre eklenerek elde edilmiştir. Dördüncü devre translinear giriş katlan ve kaskod akım aynalan kullanılarak elde edilmiştir. Önerilen devreler CMOS FTFN tasarım problemine çözüm getirmektedir. Önerilen CMOS FTFN devrelerinin serim sonrası simülasyonlan CADENCE programı ve SpectreS simülatörü yardımıyla yapılarak ve devrelerin CMOS VLSI teknolojisi ile tümleştirilebileceği gösterilmiştir. Önerilen CMOS FTFN devrelerinin performansı akım-modlu filtreler, osilatörler ve immitans simülatörleri üzerinde basan ile test edilmiştir. Aynca FTFN tabanlı devrelerin simülasyonunda ve idealsizlik analizinde kullanılmak üzere basit, yüksek doğruluklu ve lineer olmayan bir makromodel geliştirilmiştir. Bu makromodel kullanılarak baskın FTFN idealsizliklerinin filtre, immitance simülatörü ve osilatör devreleri üzerindeki etkileri belirlenmiştir. Current-mode circuits have recently gained significant attention due to their certain advantages compared to voltage-mode circuits. They offer to the designer several salient features such as inherently wide bandwidth, greater linearity, wider dynamic range, simple circuitry and low power consumption. Recently, attention has concentrated on the use of four terminal floating nullor (FTFN) in analog integrated circuit (IC) design since it has been shown that an FTFN is a more flexible and versatile building block compared to other active elements. The FTFN has been implemented with either supply current sensing method (SCSM) using an OP AMP and current mirrors or with the commercial current conveyors IC AD844 of Analog Devices in the literature. On the other hand, in modern mixed analogue/digital IC design the preferred technology is CMOS owing to low power consumption and high integration density consideration. In this thesis, four novel CMOS FTFN circuits are proposed. The first and the second CMOS FTFN circuits are obtained from suitable CMOS CCII- structure by comparing the nullor models of FTFN and CCII-. The third proposed CMOS FTFN circuit combines the advantages of a cascade of common-source and common-gate amplifiers and floating current source. The last CMOS FTFN circuit based on mixed translinear cell and cascode current mirrors. Post-layout simulation of the proposed circuits were performed using CADENCE program using SpectreS simulator. Simulation results show that the proposed CMOS FTFN circuits are suitable for CMOS VLSI technologies. Furthermore, performance of the proposed CMOS FTFN circuits were successfully tested on FTFN applications such as current-mode SITO-type filters, first order allpass filters, current-mode oscillator, universal series and parallel immitance simulators. Additionally, a simple and accurate non-linear FTFN macromodel is also introduced and basic nonideality effects of FTFN on the filters, immitance simulators and oscillators are investigated.DoktoraPh.D

A new transadmittance type first-order allpass filter employing single third generation current conveyor

A novel transadmittance (TA) mode first-order all-pass filter configuration is proposed. The proposed circuit uses a third generation current conveyor (CCIII), three resistors and a grounded capacitor. The output of the filter exhibits high output impedance so that the synthesized filter can be cascaded without additional buffers. The theoretical results are verified with PSPICE simulations using a CMOS realization of CCIII