10 research outputs found
Chemical Current-Conveyor: a new approach in biochemical computation
Biochemical sensors that are low cost, small in size and compatible with integrated circuit technology play an essential part in the drive towards personalised healthcare and the research described in this thesis is concerned with this area of medical instrumentation. A new biochemical measurement system able to sense key properties of biochemical fluids is presented. This new integrated circuit biochemical sensor, called the Chemical Current-Conveyor, uses the ion sensitive field effect transistor as the input sensor combined with the current-conveyor, an analog building-block, to produce a range of measurement systems.
The concept of the Chemical Current-Conveyor is presented together with the design and subsequent fabrication of a demonstrator integrated circuit built on conventional 0.35Όm CMOS silicon technology. The silicon area of the Chemical Current-Conveyor is (92Όm x 172Όm) for the N-channel version and (99Όm x 165Όm) for the P-channel version. Power consumption for the N-channel version is 30ΌW and 43ΌW for the P-channel version with a full load of 1MΩ. The maximum sensitivity achieved for pH measurement was 46mV per pH.
The potential of the Chemical Current Conveyor as a versatile biochemical integrated circuit, able to produce output information in an appropriate form for direct clinical use has been confirmed by applications including measurement of (i) pH, (ii) buffer index ( ), (iii) urea, (iv) creatinine and (v) urea:creatinine ratio. In all five cases the device has been demonstrated successfully, confirming the validity of the original aim of this research project, namely to produce a versatile and flexible analog circuit for many biochemical measurement applications. Finally, the thesis closes with discussion of another potential application area for the Chemical Current Conveyor and the main contributions can be summarised by the design and development of the first:
ISFET based current-conveyor biochemical sensor, called 'Chemical Current Conveyor, CCCII+' has been designed and developed. It is a general purpose biochemical analog building-block for several biochemical measurements.
Real-time buffer capacity measurement system, based on the CCCII+, which exploits the imbedded analog computation capability of the CCCII+.
Real-time enzyme based CCCII+ namely, Creatinine-CCCII+ and Urea-CCCII+ for real-time monitoring system of renal system. The system can provide outputs of 3 important parameters of the renal system, namely (i) urea concentration, (ii) creatinine concentration, and (ii) urea to creatinine ratio
Design Examples For Second Generation Current Controlled Current Conveyors And Their Applications In 28nm Process
Tez (YĂŒksek Lisans) -- Ä°stanbul Teknik Ăniversitesi, Fen Bilimleri EnstitĂŒsĂŒ, 2013Thesis (M.Sc.) -- Ä°stanbul Technical University, Institute of Science and Technology, 2013Bu çalıĆmada, gerilim modlu devrelere kıyasla sahip oldukları ĂŒstĂŒn yanlarından yararlanılarak akım modlu devrelerden ikinci kuĆak akım kontrollĂŒ akım taĆıyıcı yapılarının tasarımı ve örnek devrelerin uygulamalarının 28nm CMOS prosesinde gerçeklemeleri yapılmıĆtır. ĂalıĆmaya öncelikle karmaĆıklaĆan haberleĆme ihtiyacının meydana getirdiÄi sorunlar incelenerek baĆlanmıĆtır. Yeni standartlara uygun ve haberleĆme alanında var olan problemlere çözĂŒm öneren yapıların incelemesi yapılmÄ±Ć ve önerilecek devre yapısının saÄlaması gereken özellikler belirlenmiĆtir. Hedeflenen özelliklerin belirlenmesinin ardından tasarımı yapılacak akım kontrollĂŒ akım taĆıyıcı yapıları teorik incelemeleri ile verilmiĆ ve karakteristik özellikleri gözlenmiĆtir. Daha sonra tasarımı yapılan devre yapılarının uygulamaları olarak frekans atik filtre yapısı ile çok modlu filtre yapısı gerçeklenmiĆ ve benzetim sonuçları gözlenmiĆtir. Son olarak elde edilen yapıların serim çizimleri gerçeklenmiĆ ve sonuçlara etkileri gözlenmiĆtir. Tasarımı yapılan devreler 28nm prosesinde gerçeklenen ve önerilen aktif filtreler olması açısından önemlidir.In this study, due to their advantages over voltage mode circuits, a current mode circuit second generation current controlled current conveyors design and their applications in 28nm CMOS process realized. Initial effort was put on the investigation of current problems in communication environment and standards. With repect to literature studies and investigations, specification of the circuit to be designed defined to provide alternative sollutions. Following to this, theoretic investigations of the circuits are investigated and their characteristics are examined with the simulations. After the design of current mode circuits, frequency agile filter implementation and multi response filter implementations are selected as the application part of this study. Filter structures are realized and their characteristics observed. As the last step of this work, layout and post layout phases are executed and effects of these steps are obtained. The designed circuits and their filter applications are important since they are the first implementations in 28nm CMOS process and they provide alternative solutions to multi mode, multi response communication standards.YĂŒksek LisansM.Sc
Unconventional Circuit Elements for Ladder Filter Design
KmitoÄtovĂ© filtry jsou lineĂĄrnĂ elektrickĂ© obvody, kterĂ© jsou vyuĆŸĂvĂĄny v rĆŻznĂœch oblastech elektroniky. SouÄasnÄ tvoĆĂ zĂĄkladnĂ stavebnĂ bloky pro analogovĂ© zpracovĂĄnĂ signĂĄlĆŻ. V poslednĂ dekĂĄdÄ bylo zavedeno mnoĆŸstvĂ aktivnĂch stavebnĂch blokĆŻ pro analogovĂ© zpracovĂĄnĂ signĂĄlĆŻ. StĂĄle vĆĄak existuje potĆeba vĂœvoje novĂœch aktivnĂch souÄĂĄstek, kterĂ© by poskytovaly novĂ© moĆŸnosti a lepĆĄĂ parametry. V prĂĄci jsou diskutovĂĄny rĆŻznĂ© aspekty obvodĆŻ pracujĂcĂch v napÄĆ„ovĂ©m, proudovĂ©m a smĂĆĄnĂ©m mĂłdu. PrĂĄce reaguje na dneĆĄnĂ potĆebu nĂzkovĂœkonovĂœch a nĂzkonapÄĆ„ovĂœch aplikacĂ pro pĆenosnĂ© pĆĂstroje a mobilnĂ komunikaÄnĂ systĂ©my a na problĂ©my jejich nĂĄvrhu. PotĆeba tÄchto vĂœkonnĂœch nĂzkonapÄĆ„ovĂœch zaĆĂzenĂ je vĂœzvou nĂĄvrhĂĄĆĆŻ k hledĂĄnĂ novĂœch obvodovĂœch topologiĂ a novĂœch nĂzkonapÄĆ„ovĂœch technik. V prĂĄci je popsĂĄna Ćada aktivnĂch prvkĆŻ, jako napĆĂklad operaÄnĂ transkonduktanÄnĂ zesilovaÄ (OTA), proudovĂœ konvejor II. generace (CCII) a CDTA (Current Differencing Transconductance Amplifier). DĂĄle jsou navrĆŸeny novĂ© prvky, jako jsou VDTA (Voltage Differencing Transconductance Amplifier) a VDVTA (Voltage Differencing Voltage Transconductance Amplifier). VĆĄechny tyto prvky byly rovnÄĆŸ implementovĂĄny pomocĂ "bulk-driven" techniky CMOS s cĂlem realizace nĂzkonapÄĆ„ovĂœch aplikacĂ. Tato prĂĄce je rovnÄĆŸ zamÄĆena na nĂĄhrady klasickĂœch induktorĆŻ syntetickĂœmi induktory v pasivnĂch LC pĆĂÄkovĂœch filtrech. Tyto nĂĄhrady pak mohou vĂ©st k syntĂ©ze aktivnĂch filtrĆŻ se zajĂmavĂœmi vlastnostmi.Frequency filters are linear electric circuits that are used in wide area of electronics. They are also the basic building blocks in analogue signal processing. In the last decade, a huge number of active building blocks for analogue signal processing was introduced. However, there is still the need to develop new active elements that offer new possibilities and better parameters. The current-, voltage-, or mixed-mode analog circuits and their various aspects are discussed in the thesis. This work reflects the trend of low-power (LP) low-voltage (LV) circuits for portable electronic and mobile communication systems and the problems of their design. The need for high-performance LV circuits encourages the analog designers to look for new circuit architectures and new LV techniques. This thesis presents various active elements such as Operational Transconductance Amplifier (OTA), Current Conveyor of Second Generation (CCII), and Current Differencing Transconductance Amplifier (CDTA), and introduces novel ones, such as Voltage Differencing Transconductance Amplifier (VDTA) and Voltage Differencing Voltage Transconductance Amplifier (VDVTA). All the above active elements were also designed in CMOS bulk-driven technology for LP LV applications. This thesis is also focused on replacement of conventional inductors by synthetic ones in passive LC ladder filters. These replacements can lead to the synthesis of active filters with interesting parameters.
Low Voltage Low Power Analogue Circuits Design
DisertaÄnĂ prĂĄce je zamÄĆena na vĂœzkum nejbÄĆŸnÄjĆĄĂch metod, kterĂ© se vyuĆŸĂvajĂ pĆi nĂĄvrhu analogovĂœch obvodĆŻ s vyuĆŸitĂ nĂzkonapÄĆ„ovĂœch (LV) a nĂzkopĆĂkonovĂœch (LP) struktur. Tyto LV LP obvody mohou bĂœt vytvoĆeny dĂky vyspÄlĂœm technologiĂm nebo takĂ© vyuĆŸitĂm pokroÄilĂœch technik nĂĄvrhu. DisertaÄnĂ prĂĄce se zabĂœvĂĄ prĂĄvÄ pokroÄilĂœmi technikami nĂĄvrhu, pĆedevĆĄĂm pak nekonvenÄnĂmi. Mezi tyto techniky patĆĂ vyuĆŸitĂ prvkĆŻ s ĆĂzenĂœm substrĂĄtem (bulk-driven - BD), s plovoucĂm hradlem (floating-gate - FG), s kvazi plovoucĂm hradlem (quasi-floating-gate - QFG), s ĆĂzenĂœm substrĂĄtem s plovoucĂm hradlem (bulk-driven floating-gate - BD-FG) a s ĆĂzenĂœm substrĂĄtem s kvazi plovoucĂm hradlem (quasi-floating-gate - BD-QFG). PrĂĄce je takĂ© orientovĂĄna na moĆŸnĂ© zpĆŻsoby implementace znĂĄmĂœch a modernĂch aktivnĂch prvkĆŻ pracujĂcĂch v napÄĆ„ovĂ©m, proudovĂ©m nebo mix-mĂłdu. Mezi tyto prvky lze zaÄlenit zesilovaÄe 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 ĂșÄelem potvrzenĂ funkÄnosti a chovĂĄnĂ vĂœĆĄe zmĂnÄnĂœch struktur a prvkĆŻ byly vytvoĆeny pĆĂklady aplikacĂ, kterĂ© simulujĂ usmÄrĆovacĂ a induktanÄnĂ vlastnosti diody, dĂĄle pak filtry dolnĂ propusti, pĂĄsmovĂ© propusti a takĂ© univerzĂĄlnĂ filtry. VĆĄechny aktivnĂ prvky a pĆĂklady aplikacĂ byly ovÄĆeny pomocĂ PSpice simulacĂ s vyuĆŸitĂm parametrĆŻ technologie 0,18 m TSMC CMOS. Pro ilustraci pĆesnĂ©ho a ĂșÄinnĂ©ho chovĂĄnĂ struktur je v disertaÄnĂ prĂĄci zahrnuto velkĂ© mnoĆŸstvĂ simulaÄnĂch vĂœsledkĆŻ.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 nonâconventional ones which are bulkâdriven (BD), floatingâgate (FG), quasiâfloatingâgate (QFG), bulkâdriven floatingâgate (BDâFG) and bulkâdriven quasiâfloatingâgate (BDâQFG) techniques. The thesis also looks at ways of implementing structures of wellâknown and modern active elements operating in voltageâ, currentâ, and mixedâmode such as operational transconductance amplifier (OTA), second generation current conveyor (CCII), fullyâdifferential second generation current conveyor (FBâCCII), fullyâbalanced differential difference amplifier (FBâDDA), voltage differencing transconductance amplifier (VDTA), currentâcontrolled current differencing buffered amplifier (CCâCDBA) 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 diodeâless rectifier and inductance simulations, as well as lowâpass, bandâpass 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.
A Photoplethysmography System Optimised for Pervasive Cardiac Monitoring
Photoplethysmography is a non-invasive sensing technique which infers instantaneous
cardiac function from an optical measurement of blood vessels. This
thesis presents a photoplethysmography based sensor system that has been developed
speci fically for the requirements of a pervasive healthcare monitoring
system. Continuous monitoring of patients requires both the size and power
consumption of the chosen sensor solution to be minimised to ensure the patients
will be willing to use the device. Pervasive sensing also requires that
the device be scalable for manufacturing in high volume at a build cost that
healthcare providers are willing to accept. System level choice of both electronic
circuits and signal processing techniques are based on their sensitivity to
cardiac biosignals, robustness against noise inducing artefacts and simplicity
of implementation. Numerical analysis is used to justify the implementation
of a technique in hardware. Circuit prototyping and experimental data collection
is used to validate a technique's application. The entire signal chain
operates in the discrete-time domain which allows all of the signal processing
to be implemented in firmware on an embedded processor which minimised the
number of discrete components while optimising the trade-off between power
and bandwidth in the analogue front-end. Synchronisation of the optical illumination
and detection modules enables high dynamic range rejection of both
AC and DC independent light sources without compromising the biosignal.
Signal delineation is used to reduce the required communication bandwidth as
it preserves both amplitude and temporal resolution of the non-stationary photoplethysmography
signals allowing more complicated analytical techniques to
be performed at the other end of communication channel. The complete sensing
system is implemented on a single PCB using only commercial-off -the-shelf
components and consumes less than 7.5mW of power. The sensor platform
is validated by the successful capture of physiological data in a harsh optical
sensing environment
A Photoplethysmography System Optimised for Pervasive Cardiac Monitoring
Photoplethysmography is a non-invasive sensing technique which infers instantaneous
cardiac function from an optical measurement of blood vessels. This
thesis presents a photoplethysmography based sensor system that has been developed
speci fically for the requirements of a pervasive healthcare monitoring
system. Continuous monitoring of patients requires both the size and power
consumption of the chosen sensor solution to be minimised to ensure the patients
will be willing to use the device. Pervasive sensing also requires that
the device be scalable for manufacturing in high volume at a build cost that
healthcare providers are willing to accept. System level choice of both electronic
circuits and signal processing techniques are based on their sensitivity to
cardiac biosignals, robustness against noise inducing artefacts and simplicity
of implementation. Numerical analysis is used to justify the implementation
of a technique in hardware. Circuit prototyping and experimental data collection
is used to validate a technique's application. The entire signal chain
operates in the discrete-time domain which allows all of the signal processing
to be implemented in firmware on an embedded processor which minimised the
number of discrete components while optimising the trade-off between power
and bandwidth in the analogue front-end. Synchronisation of the optical illumination
and detection modules enables high dynamic range rejection of both
AC and DC independent light sources without compromising the biosignal.
Signal delineation is used to reduce the required communication bandwidth as
it preserves both amplitude and temporal resolution of the non-stationary photoplethysmography
signals allowing more complicated analytical techniques to
be performed at the other end of communication channel. The complete sensing
system is implemented on a single PCB using only commercial-off -the-shelf
components and consumes less than 7.5mW of power. The sensor platform
is validated by the successful capture of physiological data in a harsh optical
sensing environment
IntegriniĆł analoginiĆł filtrĆł belaidĆŸio ryĆĄio sistemoms kĆ«rimas
Disertacijoje nagrinÄjami konfigĆ«ruojami analoginiai filtrai su savaiminio derinimo grandynais, jĆł projektavimo ir ÄŻgyvendinimo bĆ«dai, kurie pritaikomi integriniĆł grandynĆł gamybos technologijoms. IĆĄkeliama ir ÄŻrodoma hipotezÄ, teigianti, kad savaiminio derinimo grandynĆł taikymas ÄŻgalina gauti integriniĆł analoginiĆł aktyviĆłjĆł rezistoriĆł kondensatoriĆł (RC) filtrĆł parametrus reikalauÂŹjamu tikslumu. Darbo tikslas â sukurti savaiminio derinimo grandynus, skirtus konfigĆ«ruojamĆł integriniĆł analoginiĆł aktyviĆłjĆł RC filtrĆł parametrĆł gavybai reikalaujamu tikslumu. Darbe iĆĄsprÄsti uĆŸdaviniai: iĆĄtirtos integriniĆł analoginiĆł aktyviĆłjĆł RC filtrĆł struktĆ«ros ir sukurti jĆł derinimo grandynĆł modeliai, pasiĆ«lytas integriniĆł analoginiĆł aktyviĆłjĆł RC filtrĆł derinimo matricĆł projektavimo bĆ«das, sukurtas ir iĆĄtirtas konfigĆ«ruojamas integrinis analoginis aktyvusis RC filtras su diskreÄiu ir tolydĆŸiu savaiminio derinimo grandynais.
DisertacijÄ
sudaro ÄŻvadas, trys skyriai, bendrosios iĆĄvados, naudotos literatĆ«ÂŹros ir autoriaus publikacijĆł disertacijos tema sÄ
raĆĄai ir penki priedai.
Äźvadiniame skyriuje aptariama tiriamoji problema, darbo aktualumas, apraĆĄomas tyrimĆł objektas, formuluojamas darbo tikslas bei uĆŸdaviniai, apraĆĄoma tyrimĆł metodika, darbo mokslinis naujumas, darbo rezultatĆł praktinÄ reikĆĄmÄ, ginamieji teiginiai, disertacijos struktĆ«ra.
Pirmame skyriuje apĆŸvelgiamos integriniĆł analoginiĆł filtrĆł struktĆ«ros, pagrindiniai parametrai bei ÄŻvardijamos parametrĆł verÄiĆł svyravimo prieĆŸastys, analizuojamos savaiminio derinimosi grandynĆł struktĆ«ros ir jĆł veikimo principai. Skyriaus pabaigoje, remiantis atlikta analize ir sudarytomis iĆĄvadomis suformuluojami disertacijos uĆŸdaviniai.
Antrajame skyriuje sudaroma konfigĆ«ruojamo integrinio analoginio filtro struktĆ«ra, skirta programine ÄŻranga valdomam radijui, sudaromi diskretaus ir tolydaus derinimo matricĆł modeliai, juos sudaranÄiĆł elementĆł verÄiĆł parinkimo algoritmai, atliekami modeliĆł ir algoritmĆł kompiuteriniai skaiÄiavimai.
TreÄiajame skyriuje, pasinaudojus sukurtais modeliais ir algoritmais, suprojektuojamas filtras su diskreÄiu ir tolydĆŸiĆł savaiminio derinimo grandynais, naudojant eksperimentinius ir kompiuterinius skaiÄiavimo metodus atliekamas suprojektuotĆł diskreÄiai ir tolydĆŸiai valdomĆł integriniĆł analoginiĆł RC filtrĆł parametrĆł bei jĆł savaiminio derinimo grandynĆł tyrimas.
Disertacijos tema yra atspausdinti 7 moksliniai straipsniai: du â mokslo ĆŸurnaluose, ÄŻtrauktuose ÄŻ Thomson Reuters Web of Science duomenĆł bazÄ, vienas â tarptautiniĆł konferencijĆł medĆŸiagoje, ÄŻtrauktoje ÄŻ Thomson Reuters Proceedings duomenĆł bazÄ, keturi â mokslo ĆŸurnaluose, referuojamose kitose tarptautinÄse duomenĆł bazÄse. Disertacijoje atliktĆł tyrimĆł rezultatai buvo pristatyti septyniose mokslinÄse konferencijose Lietuvoje ir uĆŸsienyje