Novel cascadable current-mode first order all-pass sections

This paper presents some new current mode first order all-pass sections with grounded components employing a modified current conveyor. The new circuits are ideal for current-mode cascading by possessing high output impedance. As an application of the circuits, a new quadrature oscillator is also given. The theory is validated through PSPICE simulation using 0.5μ CMOS parameters.     

Multifunctional translinear-C current-mode filter

A multifunctional current mode filter using three current controlled conveyors and two grounded capacitors is described. The filter realizes high pass, band pass and low pass second order current transfer functions, and provides independent pole-ω ₀, and pole-Q ₀ tuning through external current control. The filter also displays low incremental parameter sensitivities. The simulation results on the filter support the theory.     

General configuration for realizing current-mode first-order all-pass filter using DVCC

In this paper, a new general configuration for realizing current-mode all-pass filter circuits using differential voltage current conveyor (DVCC) is proposed. The proposed configuration is composed of a DVCC and five passive admittances. However, each of the circuits extracted from the proposed configuration uses only three passive elements. As an application, the proposed configuration is used to construct a quadrature oscillator. The theoretical results are verified by SPICE simulations.     

Implementation of 2-D denominator-separable digital filters using first-order all-pass sections

It is established that denominator-separable transfer functions which characterize an important subclass of 2-D filters can be expressed as a linear combination of first-order (1-D or 2-D separable) all-pass transfer functions with real or complex coefficients. This type of expansion is referred to as all-pass expansion of the corresponding transfer function. Based on this all-pass expansion, we derive some efficient structures for the realization of 2-D denominator-separable filters using all-pass sections.On leave from S.V. University College of Engineering. Tirupati-517502, India.     

A BJT technology-based current-mode tunable all-pass filter

In this paper, a new bipolar technology-based configuration for providing inverting first-order current-mode (CM) all-pass filter response is proposed. One of the main advantages of the introduced active C topology is to have the property of electronic tunability of its pole frequency without requiring passive component matching condition. To show the performance of suggested filter, simulations are achieved by means of PSPICE program. Moreover, experimental test results are included.     

Resistorless first-order all-pass filter with electronic tuning

A first-order all-pass filter (APF) with electronic tuning properties is presented. The filter consists of only active components and a single-grounded capacitor. The circuit is cascadable, has small sensitivities, and suitable for monolithic integration, and it can also operate at high frequencies.     

A Resistorless realization of the first-order all-pass filter

All-pass filters are widely used to shift the phase of an analog signal without altering its magnitude. In this study, a new realization of all-pass filter using one current controlled conveyor (CCCII), one operational amplifier (OP-AMP) and two capacitors is presented. The proposed circuit does not use any resistors thus it is suitable for easy integration. Also the pole frequency of the proposed circuit can be tuned electronically. Simulation results are included to verify theory.     

Electronically tunable current-mode square-root-domain first-order multifunction filter

In this article, a new current-mode square-root-domain first-order multifunction filter is designed. The filter circuit has a very simple structure; it uses only the Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) and a grounded capacitor. All transistors’ aspect ratios are the same. It provides lowpass, highpass and allpass responses simultaneously for a single input signal. It can be electronically tuned by changing an external DC current. The filter operates with a single supply voltage of 2.5 V. The proposed circuit has been simulated with PSPICE electronics circuit simulation program (Cadence OrCAD Capture CIS Version 9.2) simulation programs using TSMC 0.35 μm (Taiwan Semiconductor Manufacturing Company) Complementary Metal-Oxide-Semiconductor (CMOS) process parameters.     

NOVEL REALIZATION OF FIRST-ORDER ALL-PASS NETWORKS USING CURRENT CONVEYER

Two novel networks for realizing first-order all-pass transfer functions are intro-duced. The networks use a current conveyer, a buffer and only three passive elements, and theyexhibit a high input impedance.     

New realisations of first-order two-dimensional all-pass andall-pole digital filters

A number of stable and lossless first-order two-dimensional all-pass and all-pole digital filter structures each with two delays, two multipliers, and six adders are presented. Owing to the losslessness property, zero-input oscillations can easily be eliminated by magnitude truncations. The resultant structures are modular and are suitable for VLSI implementation     

Wide-band resistorless all-pass sections with single element tuning

This paper presents three first order resistorless all-pass filters using combinations of current controlled current conveyors (CCCII) and a unity gain buffer. All circuits feature single element tuning, low sensitivities, and low output impedances, therefore they are suitable for cascading. Circuit simulation results are found in good agreement with theoretical analysis.     

Low-voltage first-order fully differential CMOS all-pass filter with programmable pole-zero

A simple modification of the conventional first-order all-pass filter is introduced that provides it with a low-voltage fully differential operation with programmable pole-zero frequency. The modification is based on the inverting op-amp configuration and uses operational transconductance amplifiers instead of resistors not needing a buffered signal source or buffered op-amps as the conventional all-pass does. Experimental results verify that tuning capability is provided.     

Derivation of low-power first-order low-pass,high-pass and all-pass filters

In this letter, a new voltage-mode (VM) configuration for providing low-power and simultaneous realization of first-order low-pass, high-pass and all-pass filters is presented. The output of the all-pass filter is taken differentially. The proposed circuit contains low number of components, i.e., only two NMOS transistors, a floating battery, a grounded capacitor and a floating resistor. Adding two NMOS transistors to the proposed circuit it is modified as an all-pass filter with a single-ended output. The main advantage of the presented circuits in comparison with other counterparts is their extremely low power dissipation. Moreover, the floating resistor can be replaced with an additional NMOS transistor in triode region to provide electronic tunability. Simulation results using SPICE program are given to demonstrate the performance of the proposed circuit.     

Novel first order all-pass sections using a single CCIII

Two novel first order voltage-mode all-pass sections using a single third generation current conveyor (CCIII) are given. In addition the first circuit uses three resistors and one capacitor and the second circuit which is derived from the first circuit uses two resistors and one capacitor. A current-mode first order all-pass section requiring one capacitor and one resistor is also proposed. SPICE simulation results are incorporated to verify the theory.     

Simple first order all-pass section using a single CCII

A novel first order all-pass section using a single second generation current conveyor is given. In addition the circuit uses two resistors and only one capacitor. The circuit is also realized with a translinear conveyor. The latter circuit uses only one external resistor and a capacitor. The proposed circuits are verified using PSPICE with attractive results.     

Resistorless realization of current-mode first-order allpass filter using current differencing transconductance amplifiers

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.     

High output impedance current-mode first-order allpass networks with four grounded components and two CCIIs

Eight current-mode first-order allpass networks using second-generation current conveyors (CCII) are presented. Each of the proposed circuits employs two CCIIs, two grounded capacitors and two grounded resistors. The networks offer high output impedances. Experimental results are also included.     

Low-sensitivity universal first-order digital filter sections without limit cycles

Two new universal digital structures simultaneously realising at different outputs all types of first-order filter transfer function (lowpass, highpass and allpass) are proposed. The structures use a canonical number of multipliers and delays, are limit-cycle-free and with low sensitivities, and are convenient for VLSI implementation of universal chips.<>     

Supplementary all-pass sections with reduced number of passive elements using a single current conveyor

Four new configurations realizing current conveyor-based first-order all-pass filters are proposed. Using these configurations two types of first-order voltage-mode allpass filter can be realized. The circuits employ a single positive type secondgeneration current conveyor (CCII+) and only three passive components. For each topology only a simple component matching constraint is required. To illustrate the design possibilities provided by the introduced circuits an oscillator circuit consisting of the proposed all-pass filters is constructed and experimentally tested.