Current-Mode Dual-Phase Precision Full-Wave Rectifier Using Current-Mode Two-Cell Winner-Takes-All (WTA) Circuit

In addition to the recently proposed full-wave rectifier by Prommee et al. using voltage-mode (VM)two-cell winner-takes-all (WTA) circuit, we present current-mode (CM) precision full-wave rectifier using CM two-cell WTA circuit. The popular Lazzaro’s CM WTA circuit has been employed for the purpose and there is no requirement of inverting the input signal. Also, dual complimentary phases of the output current signal are available from high-output impedance terminals for explicit utilization. As compared to many recently proposed CM rectifiers using complex active devices, e.g. dual-X current conveyor or universal voltage conveyor, our circuit is very compact and requires a total of 21 transistors. SPICE simulation results of the circuit implemented using 0.35 um TSMC CMOS technology are provided which verify the workability of the proposed circuit

Utilizing Unconventional CMOS Techniques for Low Voltage Low Power Analog Circuits Design for Biomedical Applications

Tato disertační práce se zabývá navržením nízkonapěťových, nízkopříkonových analogových obvodů, které používají nekonvenční techniky CMOS. Lékařská zařízení na bateriové napájení, jako systémy pro dlouhodobý fyziologický monitoring, přenosné systémy, implantovatelné systémy a systémy vhodné na nošení, musí být male a lehké. Kromě toho je nutné, aby byly tyto systémy vybaveny baterií s dlouhou životností. Z tohoto důvodu převládají v biomedicínských aplikacích tohoto typu nízkopříkonové integrované obvody. Nekonvenční techniky jako např. využití transistorů s řízeným substrátem (Bulk-Driven “BD”), s plovoucím hradlem (Floating-Gate “FG”), s kvazi plovoucím hradlem (Quasi-Floating-Gate “QFG”), s řízeným substrátem s plovoucím hradlem (Bulk-Driven Floating-Gate “BD-FG”) a s řízeným substrátem s kvazi plovoucím hradlem (Bulk-Driven Quasi-Floating-Gate “BD-QFG”), se v nedávné době ukázaly jako efektivní prostředek ke zjednodušení obvodového zapojení a ke snížení velikosti napájecího napětí směrem k prahovému napětí u tranzistorů MOS (MOST). V práci jsou podrobně představeny nejdůležitější charakteristiky nekonvenčních technik CMOS. Tyto techniky byly použity pro vytvoření nízko napěťových a nízko výkonových CMOS struktur u některých aktivních prvků, např. Operational Transconductance Amplifier (OTA) založené na BD, FG, QFG, a BD-QFG techniky; Tunable Transconductor založený na BD MOST; Current Conveyor Transconductance Amplifier (CCTA) založený na BD-QFG MOST; Z Copy-Current Controlled-Current Differencing Buffered Amplifier (ZC-CC-CDBA) založený na BD MOST; Winner Take All (WTA) and Loser Take All (LTA) založený na BD MOST; Fully Balanced Four-Terminal Floating Nullor (FBFTFN) založený na BD-QFG technice. Za účelem ověření funkčnosti výše zmíněných struktur, byly tyto struktury použity v několika aplikacích. Výkon navržených aktivních prvků a příkladech aplikací je ověřován prostřednictvím simulačních programů PSpice či Cadence za použití technologie 0.18 m CMOS.This doctoral thesis deals with designing ultra-low-voltage (LV) low-power (LP) analog circuits utilizing the unconventional CMOS techniques. Battery powered medical devices such as; long term physiological monitoring, portable, implantable, and wearable systems need to be small and lightweight. Besides, long life battery is essential need for these devices. Thus, low-power integrated circuits are always paramount in such biomedical applications. Recently, unconventional CMOS techniques i.e. Bulk-Driven (BD), Floating-Gate (FG), Quasi-Floating-Gate (QFG), Bulk-Driven Floating-Gate (BD-FG) and Bulk-Driven Quasi-Floating-Gate (BD-QFG) MOS transistors (MOSTs) have revealed as effective devices to reduce the circuit complexity and push the voltage supply of the circuit towards threshold voltage of the MOST. In this work, the most important features of the unconventional CMOS techniques are discussed in details. These techniques have been utilized to perform ultra-LV LP CMOS structures of several active elements i.e. Operational Transconductance Amplifier (OTA) based on BD, FG, QFG, and BD-QFG techniques; Tunable Transconductor based on BD MOST; Current Conveyor Transconductance Amplifier (CCTA) based on BD-QFG MOST; Z Copy-Current Controlled-Current Differencing Buffered Amplifier (ZC-CC-CDBA) based on BD MOST; Winner Take All (WTA) and Loser Take All (LTA) based on BD MOST; Fully Balanced Four-Terminal Floating Nullor (FBFTFN) based on BD-QFG technique. Moreover, to verify the workability of the proposed structures, they were employed in several applications. The performance of the proposed active elements and their applications were investigated through PSpice or Cadence simulation program using 0.18 m CMOS technology.

Low Voltage Low Power Analogue Circuits Design

Disertační práce je zaměřena na výzkum nejběžnějších metod, které se využívají při návrhu analogových obvodů s využití nízkonapěťových (LV) a nízkopříkonových (LP) struktur. Tyto LV LP obvody mohou být vytvořeny díky vyspělým technologiím nebo také využitím pokročilých technik návrhu. Disertační práce se zabývá právě pokročilými technikami návrhu, především pak nekonvenčními. Mezi tyto techniky patří využití prvků s řízeným substrátem (bulk-driven - BD), s plovoucím hradlem (floating-gate - FG), s kvazi plovoucím hradlem (quasi-floating-gate - QFG), s řízeným substrátem s plovoucím hradlem (bulk-driven floating-gate - BD-FG) a s řízeným substrátem s kvazi plovoucím hradlem (quasi-floating-gate - BD-QFG). Práce je také orientována na možné způsoby implementace známých a moderních aktivních prvků pracujících v napěťovém, proudovém nebo mix-módu. Mezi tyto prvky lze začlenit zesilovače typu OTA (operational transconductance amplifier), CCII (second generation current conveyor), FB-CCII (fully-differential second generation current conveyor), FB-DDA (fully-balanced differential difference amplifier), VDTA (voltage differencing transconductance amplifier), CC-CDBA (current-controlled current differencing buffered amplifier) a CFOA (current feedback operational amplifier). Za účelem potvrzení funkčnosti a chování výše zmíněných struktur a prvků byly vytvořeny příklady aplikací, které simulují usměrňovací a induktanční vlastnosti diody, dále pak filtry dolní propusti, pásmové propusti a také univerzální filtry. Všechny aktivní prvky a příklady aplikací byly ověřeny pomocí PSpice simulací s využitím parametrů technologie 0,18 m TSMC CMOS. Pro ilustraci přesného a účinného chování struktur je v disertační práci zahrnuto velké množství simulačních výsledků.The dissertation thesis is aiming at examining the most common methods adopted by analog circuits' designers in order to achieve low voltage (LV) low power (LP) configurations. The capability of LV LP operation could be achieved either by developed technologies or by design techniques. The thesis is concentrating upon design techniques, especially the non–conventional ones which are bulk–driven (BD), floating–gate (FG), quasi–floating–gate (QFG), bulk–driven floating–gate (BD–FG) and bulk–driven quasi–floating–gate (BD–QFG) techniques. The thesis also looks at ways of implementing structures of well–known and modern active elements operating in voltage–, current–, and mixed–mode such as operational transconductance amplifier (OTA), second generation current conveyor (CCII), fully–differential second generation current conveyor (FB–CCII), fully–balanced differential difference amplifier (FB–DDA), voltage differencing transconductance amplifier (VDTA), current–controlled current differencing buffered amplifier (CC–CDBA) and current feedback operational amplifier (CFOA). In order to confirm the functionality and behavior of these configurations and elements, they have been utilized in application examples such as diode–less rectifier and inductance simulations, as well as low–pass, band–pass and universal filters. All active elements and application examples have been verified by PSpice simulator using the 0.18 m TSMC CMOS parameters. Sufficient numbers of simulated plots are included in this thesis to illustrate the precise and strong behavior of structures.

Precizni dvostrani usmerivači malih signala realizovani u tehnici strujnog procesiranja

REZIME: Obrada analognih signala može se izvoditi u tehnici naponskog ili strujnog procesiranja. Iako je naponsko procesiranje imalo dominantniju ulogu u obradi signala dugi niz godina, pojavom strujnih prenosnika, strujno procesiranje dobija na značaju u poslednjih dvadesetak godina zbog više svojih prednosti koje su dokazane na primerima preciznih dvostranih usmerača za male signale obrađenih i u ovoj tezi. Pre svega prednost se ogleda u povećanju širine propusnog opsega zbog upotrebe opterećenja male impedanse. Predmet disertacije je realizacija preciznih dvostranih usmerača za signale malih amplituda u tehnici strujnog procesiranja. Precizno usmeravanje je važna funkcija obrade signala koja ima izuzetnu važnost kod mnogih mernih uređaja kao što su voltmetri i ampermetri za naizmenične signale, detektori polariteta signala, detektori vršne vrednosti, detektori amplitudno-modulisanih signala, kola za usrednjavanje signala itd.. Nakon opisa tehnike strujnog procesiranja i prikaza translinearnog principa, kao polazne osnove za realizaciju brojnih nelinearnih kola u bipolarnoj tehnologiji, razmatran je koncept strujnog prenosnika sa posebnim osvrtom na strujnom prenosniku druge vrste sa bipolarnim tranzistorima. Opisan je i koncept operacionog prenosnika, a sa posebnom pažnjom obrađen je operacioni prenosnik druge vrste sa strujnim kormilarenjem. Dat je i prikaz uporedne analize preciznih dvostranih usmerača realizovanih u tehnici naponskog procesiranja kao i u tehnici strujnog procesiranja, sa prednostima i manama jednih u odnosu na druge. U disertaciji su predstavljena dva modela preciznog dvostranog usmerača za male signale, od kojih prvi model koristi operacioni prenosnik, četiri strujna ogledala i dva strujna izvora, dok je drugi model realizovan sa dva operaciona prenosnika i dve diode sa predpolarizacijom. Osobine realizovanih usmerača su znatno bolje u odnosu na usmerače realizovane sa istim elektronskim komponentam u tehnici naponskog procesiranja. Kroz simulacionu i eksperimentalnu proveru dokazano je da je moguće realizovati precizni dvostrani usmerač u tehnici strujnog procesiranja koji radi u širokom frekventnom opsegu, za signale male amplitude, upotrebom dve diode umesto četiri, kako je to do sada uglavnom rađeno. Takođe je pokazano da ovakav usmerač ima sve bitne osobine bolje od osobina usmerača realizovanog u tehnici naponskog procesiranja.SUMMARY: The processing of analog signals can be performed in the voltage or current processing technique. Although the voltage processing has had a more dominant role in signal processing for many years, with the adventages of current conveyors, current processing has become more important over the past twenty years due to its manifold advantages, which have been proved by examples of precision full wave rectifiers for small signals dealt with in this thesis. The first advantage is the in increase of the bandwidth due to the use of a small impedance load. The subject of the doctoral thesis is the realization of full-wave rectifier for small amplitude signals in a current mode processing techniques. Precise rectification is an important function of signal processing and it is highly significant in many measuring devices, such as voltmeters, ammeters for alternating signals, detectors, signal polarity detectors, peak detectors, amplitude-modulated signal detectors, averaging circuits, etc... The dissertation presents the description of a current processing technique and translinear principle as an initial point for the realization of numerous nonlinear circuits in bipolar technology. This is followed by a speculation on a concept of current conveyor, where a special focus is placed on a different type of current conveyor with bipolar transistors. In addition, the concept of operational conveyor is given with an emphasis on a different type of operational conveyor with current steering output stage. The thesis also presents a comparative analysis of full-wave rectifiers, which are realized in both, voltage and current processing techniques, as well as their advantages and disadvantages compared to each other. The dissertation presents two models of precision full-wave rectifier for low-level signals, as well as the realization of the rectifiers out of which one uses an operational conveyor and four current mirrors and two direct current sources, while another one has two operational conveyors and two diodes with polarization before of them. The characteristics of such rectifiers are significantly better compared to the rectifiers with the same electronic components in voltage processing technique. Through simulation and experimental verification it has been proved that the full-wave rectifier in a current processing technique can be realized for wide frequency range, for low amplitude signals, by using two diodes instead of four, as it has been mostly done so far. It was also shown that such rectifiers have better characteristics than the rectifiers realized in voltage processing mode

Full-wave recifier based on differential difference current conveyor for LV LP application

In this paper, two full-wave voltage mode and current mode precision rectifiers based on bulk-driven quasi floating-gate (BD-QFG) differential difference current conveyor (DDCC) are presented. The rectifiers are capable to operate under ultra-low voltage (LV) of ±0.3 V and consume extremely low power (LP) in micro range. Moreover, these rectifiers enjoy circuit simplicity, whereas the voltage mode rectifier designed using only two BD-QFG DDCCs, and the current mode rectifier is constructed from only one BD-QFG DDCC and one SOD523 diode from NXP Semiconductor. Thus their circuits are suitable for IC fabrication. Both rectifiers yield better performance in view of the minimum number of devices, reduced power consumption and acceptable operation frequency. The performance of these rectifiers is investigated through PSPICE simulation program using 0.18 μm CMOS technology from TSMC