KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 6 of 6
  • Some of the metrics are blocked by your 
    Item type:Item,
    Synthesis of current differencing transconductance amplifier-based current limiters and its applications
    (2011-04-01)
    Tangsrirat, Worapong
    ;
    Pukkalanun, Tattaya
    ;
    Surakampontorn, Wanlop
    A synthesis of analog current limiter (CL) building blocks based on a current differencing transconductance amplifier (CDTA) is proposed. The breakpoint and the slope of the resulting transfer characteristic obtained from the proposed CDTA-based CL are electronically programmable through the external bias currents. To demonstrate versatility of the proposed electronically tunable CLs, some nonlinear applications to programmable current-mode precision full-wave rectifiers and piecewise-linear function approximation generators are also presented. PSPICE simulation and experimental results confirm the effectiveness of the proposed circuits. © 2011 World Scientific Publishing Company.
  • Some of the metrics are blocked by your 
    Item type:Item,
    Simple current-mode analog multiplier, divider, square-rooter and squarer based on CDTAs
    (2011-03-01)
    Tangsrirat, Worapong
    ;
    Pukkalanun, Tattaya
    ;
    Mongkolwai, Pratya
    ;
    Surakampontorn, Wanlop
    In this paper, the design of simple analog current-mode multiplier, divider, square-rooter and squarer circuits using only two current differencing transconductance amplifiers (CDTAs) is proposed. With the selection of the applied input currents, the proposed circuit can perform four-quadrant current multiplication, division and current-controlled current amplification, without changing its configuration. Moreover, the current-mode square-rooter and squarer circuits can easily be obtained with the possibility of electronically transfer gain adjustment by slight modification of the proposed configuration. All the proposed circuits are insensitive to ambient temperature variations. Additionally, the CDTA non-ideality effects on the proposed circuits are also investigated and discussed. The performances of the realized circuits are examined by PSPICE simulations. © 2010 Elsevier GmbH. All rights reserved.
  • Some of the metrics are blocked by your 
    Item type:Item,
    Resistorless realization of current-mode first-order allpass filter using current differencing transconductance amplifiers
    (2010-02-01)
    Tangsrirat, Worapong
    ;
    Pukkalanun, Tattaya
    ;
    Surakampontorn, Wanlop
    This paper presents a realization of a current-mode first-order allpass filter using two current differencing transconductance amplifiers (CDTAs) as the active components and one virtually grounded capacitor as the only passive component. The proposed filer requires no external resistor and is electronically adjustable by varying the external bias current of the CDTA. No component-matching constraints are required. The circuit realizes both inverting and non-inverting types of allpass filters, and also exhibits high-output impedances, which are easy cascading in the current-mode operation. As an application of the proposed CDTA-based allpass section, a current-mode quadrature oscillator is realized. PSPICE simulation results are given to confirm the theoretical analysis. © 2010 Elsevier Ltd. All rights reserved.
  • Some of the metrics are blocked by your 
    Item type:Item,
    Cascadable current-mode multifunction filter with two inputs and three outputs using CDTAs
    (2007-12-01)
    Dumawipata, Teerasilapa
    ;
    Tangsrirat, Worapong
    ;
    Surakampontorn, Wanlop
    The current-controlled current-mode universal filter with two inputs and three outputs using current differencing transconductance amplifiers (CDTAs) as active components is presented. The proposed circuit configuration consisting of only three CDTAs and two grounded capacitors exhibits low-input and high-output impedances, which is advantageous from an integration point of view and is important for easy cascading in the current-mode operations. By properly connecting the input and output terminals, the filter can simultaneously realize all the standard filter functions, namely lowpass (LP), bandpass (BP), highpass (HP), bandstop (BS) and allpass (AP), without any component matching conditions. The natural angular frequency (ω<inf>o</inf>) and the bandwidth (ω<inf>o</inf>/Q) of the proposed filters can be electronically controlled, thanks to the tunability properties of the CDTAs. All the passive and active sensitivities are low. SPICE simulation results are included to confirm the theory. ©2007 IEEE.
  • Some of the metrics are blocked by your 
    Item type:Item,
    Multiple-input single-output current-mode multifunction filter using current differencing transconductance amplifiers
    (2007-04-02)
    Tangsrirat, Worapong
    ;
    Dumawipata, Teerasilapa
    ;
    Surakampontorn, Wanlop
    A novel current-controlled multiple-input single-output current-mode universal filter employing current differencing transconductance amplifiers (CDTAs) as active elements is described. The proposed circuit offers the following attractive features: employment of the minimum number of active and passive components; simultaneous realization of all the standard filtering functions; independent current-control of the parameters ω<inf>o</inf> and ω<inf>o</inf> / Q; no requirement of component matching conditions; employment of only two grounded passive capacitors which is suitable for integrated circuit (IC) implementation; and low passive and active sensitivities. PSPICE simulation results are given to verify the theoretical analysis. An example application using the proposed circuit in cascade realization of the high-order current-mode filter is also presented. © 2006 Elsevier GmbH. All rights reserved.
  • Some of the metrics are blocked by your 
    Item type:Item,
    Systematic realization of cascadable current-mode filters using current differencing transconductance amplifiers
    (2006-01-01)
    Tangsrirat, Worapong
    ;
    Surakampontorn, Wanlop
    In this paper, a variety of cascadable current-mode filter architectures incorporating current differencing transconductance amplifiers (CDTAs) and grounded passive elements are realized. The proposed filter topologies mainly contain the CDTA-based cascaded filter structure and the current feedback loop, which provides a systematic and structural method for realizing general filtering functions. They are convenient for integration, electronically tunable, easy cascadability, of low sensitivity, simple in structure and easy to design. Design examples and simulation results by PSPICE confirm the usefulness of the proposed approach.