3 research outputs found
Electronically Tunable Single-Input Multi-Output Current- Mode Biquad Filter Suitable for Easy Cascading
This paper presents a new current-mode (CM) multi-function filter with one input and three outputs. The filter uses only three multi-output inverting second generation current conveyors (ICCIIs), two grounded capacitors and two MOS resistors. Without using any external passive elements, the proposed circuit can simultaneously realize lowpass (LP), bandpass (BP) and highpass (HP) responses without any matching or cancellation conditions, all at high impedance outputs which is important for easy cascading in CM operation. The bandstop (BS) and allpass (AP) responses can be obtained by connecting appropriate output currents directly without using additional active elements. The parameters Ïo and Q, can be electronically tuned by adjusting the bias voltages of the MOS resistances. The proposed circuit enjoys low sensitivities
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.
Fully-Differential Frequency Filters with Modern Active Elements
Tato disertaÄnĂ prĂĄce se zamÄĆuje na vĂœzkum v oblasti frekvenÄnĂch filtrĆŻ. HlavnĂm cĂlem je navrhnout a analyzovat plnÄ diferenÄnĂ kmitoÄtovĂ© filtry pracujĂcĂ v proudovĂ©m mĂłdu a vyuĆŸĂvajĂcĂ modernĂ aktivnĂ prvky. PrezentovanĂ© filtry jsou navrĆŸeny za pouĆŸitĂ proudovĂœch sledovaÄĆŻ, operaÄnĂch transkonduktanÄnĂch zesilovaÄĆŻ, plnÄ diferenÄnĂch proudovĂœch zesilovaÄĆŻ a transrezistanÄnĂch zesilovaÄĆŻ. NĂĄvrh se zamÄĆuje na moĆŸnost ĆĂdit nÄkterĂœ z typickĂœch parametrĆŻ filtru pomocĂ ĆiditelnĂœch aktivnĂch prvkĆŻ, kterĂ© jsou vhodnÄ umĂstnÄny do obvodovĂ© struktury. JednotlivĂ© prezentovanĂ© filtry jsou navrĆŸeny v nediferenÄnĂ a diferenÄnĂ verzi. VelkĂœ dĆŻraz je vÄnovĂĄn srovnĂĄnĂ plnÄ diferenÄnĂch struktur s jejich odpovĂdajĂcĂmi nediferenÄnĂmi formami. FunkÄnost jednotlivĂœch nĂĄvrhĆŻ je ovÄĆena simulacemi a v nÄkterĂœch pĆĂpadech i experimentĂĄlnĂm mÄĆenĂm.This doctoral thesis focuses on research in the field of frequency filters. The main goal is to propose and analyze fully-differential current-mode frequency filters employing modern active elements. Presented filters are proposed using current followers, operational transconductance amplifiers, digitally adjustable current amplifiers and transresistance amplifiers. The proposal is focusing on ability to control some of the typical filter parameter or parameters using controllable active elements suitably placed in the circuit structure. Individual presented filters are proposed in their single-ended and fully-differential forms. Great emphasis is paid to a comparison of the fully-differential structures and their corresponding single-ended forms. The functionality of each proposal is verified by simulations and in some cases also by experimental measurements.