52 research outputs found
Single-input Multiple-output Tunable Log-domain Current-mode Universal Filter
This paper describes the design of a current-mode single-input multiple-output (SIMO) universal filter based on the log-domain filtering concept. The circuit is a direct realization of a first-order differential equation for obtaining the lossy integrator circuit. Lossless integrators are realized by log-domain lossy integrators. The proposed filter comprises only two grounded capacitors and twenty-four transistors. This filter suits to operate in very high frequency (VHF) applications. The pole-frequency of the proposed filter can be controlled over five decade frequency range through bias currents. The pole-Q can be independently controlled with the pole-frequency. Non-ideal effects on the filter are studied in detail. A validated BJT model is used in the simulations operated by a single power supply, as low as 2.5 V. The simulation results using PSpice are included to confirm the good performances and are in agreement with the theory
ECCCII-Based Current-Mode Universal Filter with Orthogonal Control of w_o and Q
This paper presents a new current-mode current-controlled four-input five-output universal filter employing one current-controlled current conveyor (CCCII), one electronically tunable CCCII and two grounded capacitors. The proposed configuration provides lowpass, bandpass, highpass, bandstop and allpass current responses that taken from the high-output impedance terminals, which enable easy cascadability of the current-mode operation. The filter also offers both orthogonal and electronic controls of the natural frequency and the quality factor through adjusting the bias current of the CCCIIs. For realizing all the filter responses, the proposed filter does not require passive component-matching condition and both active and passive sensitivities are low. In addition, a new current-mode current-controlled single-input five-output universal filter can be achieved by using an additional multiple-output minus-type CCCII. The proposed filter is simulated using PSPICE simulations to confirm the theoretical analysis
Low-Voltage High-Linearity Wideband Current Differencing Transconductance Amplifier and Its Application on Current-Mode Active Filter
A low-voltage high-linearity wideband current differencing transconductance ampliïŹer (CDTA) is presented in this paper. The CDTA consists of a current differencing circuit and a cross-coupling transconductance circuit. The PSPICE simulations of the proposed CDTA show a good performance: -3dB frequency bandwith is about 900 MHz, low power consumption is 2.48 mW, input current linear range is ±100 ”A and low current-input resistance is less than 20 âŠ, high current-output resistance is more than 3 MâŠ. PSpice simulations for a current-mode universal filter and a proposed high-order filter are also conducted, and the results verify the validity of the proposed CDTA
Voltage-Mode Multifunction Biquadratic Filters Using New Ultra-Low-Power Differential Difference Current Conveyors
This paper presents two low-power voltage-mode multifunction biquadratic filters using differential difference current conveyors. Each proposed circuit employs three differential difference current conveyors, two grounded capacitors and two grounded resistors. The low-voltage ultra-low-power differential difference current conveyor is used to provide low-power consumption of the proposed filters. By appropriately connecting the input and output terminals, the proposed filters can provide low-pass, band-pass, high-pass, band-stop and all-pass voltage responses at high-input terminals, which is a desirable feature for voltage-mode operations. The natural frequency and the quality factor can be orthogonally set by adjusting the circuit components. For realizing all the filter responses, no inverting-type input signal requirements as well as no component-matching conditional requirements are imposed. The incremental parameter sensitivities are also low. The characteristics of the proposed circuits are simulated by using PSPICE simulators to confirm the presented theory
Switched-current filter structure for synthesizing arbitrary characteristics based on follow-the-leader feedback configuration
This document is the Accepted Manuscript version of the following article: Wenshan Zhao, Yigang He, and Yichuang Sun, âSwitched-current filter structure for synthesizing arbitrary characteristics based on follow-the-leader feedback configurationâ, Analog Integrated Circuits and Signal Processing, (2015), Vol. 82 (2): 479-486. The version of record is available online at doi: 10.1007/s10470-014-0477-8 © Springer Science+Business Media New York 2015Peer reviewedFinal Accepted Versio
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.
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