Tunable Versatile High Input Impedance Voltage-Mode Universal Biquadratic Filter Based on DDCCs

A high input impedance voltage-mode universal biquadratic filter with three input terminals and seven output terminals is presented. The proposed circuit uses three differential difference current conveyors (DDCCs), four resistors and two grounded capacitors. The proposed circuit can realize all the standard filter functions, namely, lowpass, bandpass, highpass, notch and allpass, simultaneously. The proposed circuit offers the features of high input impedance, using only grounded capacitors, and orthogonal controllability of resonance angular frequency and quality factor

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

A Novel (DDCC-SFG)-Based Systematic Design Technique of Active Filters

This paper proposes a novel idea for the synthesis of active filters that is based on the use of signal-flow graph (SFG) stamps of differential difference current conveyors (DDCCs). On the basis of an RLC passive network or a filter symbolic transfer function, an equivalent SFG is constructed. DDCCs’ SFGs are identified inside the constructed ‘active’ graph, and thus the equivalent circuit can be easily synthesized. We show that the DDCC and its ‘derivatives’, i.e. differential voltage current conveyors and the conventional current conveyors, are the main basic building blocks in such design. The practicability of the proposed technique is showcased via three application examples. Spice simulations are given to show the viability of the proposed technique

High Input Impedance Voltage-Mode Universal Biquadratic Filters With Three Inputs Using Three CCs and Grounding Capacitors

Two current conveyors (CCs) based high input impedance voltage-mode universal biquadratic filters each with three input terminals and one output terminal are presented. The first circuit is composed of three differential voltage current conveyors (DVCCs), two grounded capacitors and four resistors. The second circuit is composed of two DVCCs, one differential difference current conveyor (DDCC), two grounded capacitors and four grounded resistors. The proposed circuits can realize all the standard filter functions, namely, lowpass, bandpass, highpass, notch and allpass filters by the selections of different input voltage terminals. The proposed circuits offer the features of high input impedance, using only grounded capacitors and low active and passive sensitivities. Moreover, the x ports of the DVCCs (or DDCC) in the proposed circuits are connected directly to resistors. This design offers the feature of a direct incorporation of the parasitic resistance at the x terminal of the DVCC (DDCC), Rx, as a part of the main resistance

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

New CMOS Realization of Voltage Differencing Buffered Amplifier and Its Biquad Filter Applications

In this paper, new biquad filter configuration using a recently introduced active element, namely Voltage Differencing Buffered Amplifier (VDBA), is proposed. This block has high impedance input terminals and low impedance output terminal, providing advantages at voltage mode circuits. Besides, VDBA has a transconductance gain, thus the proposed circuits can be employed without using any external resistors. Two new voltage-mode biquad filter configurations are presented for VDBA application. Each proposed filter employs two active elements and two or three passive components. Filters, having three inputs and single output, can realize voltage-mode low-pass, band-pass, high-pass, band-stop, and all-pass filters. The biquad filters have low output impedances that is necessity for cascadability for voltage mode circuits, and no critical component matching conditions are required. For the second biquad, quality factor can be adjusted via resistor independently of the natural frequency. Simulation results are given to, confirming the theoretical analysis. The proposed biquad filters are simulated using TSMC CMOS 0.35 µm technology. LTSPICE simulations of the proposed circuits give results that agree well with the theoretical analysis

High-Order Current-Mode and Transimpedance-Mode Universal Filters with Multiple-Inputs and Two-Outputs Using MOCCIIs

A high-order current-mode and transimpedance-mode universal filter with multiple-inputs and two-outputs based on multiple output second-generation current conveyors (MOCCIIs) is introduced. By choosing the input current terminals appropriately, the current-mode and transimpedance-mode lowpass, bandpass, highpass, notch or allpass filters can be obtained without component matching conditions. The proposed nth order universal filter requires (n+1) MOCCIIs, (n+1) resistors and n grounded capacitors. As examples, the first-order, biquadratic and third-order universal filters are given and compared with previous published works

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

Versatile Tunable Current-Mode Universal Biquadratic Filter Using MO-DVCCs and MOSFET-Based Electronic Resistors

This paper presents a versatile tunable current-mode universal biquadratic filter with four-input and three-output employing only two multioutput differential voltage current conveyors (MO-DVCCs), two grounded capacitors, and a well-known method for replacement of three grounded resistors by MOSFET-based electronic resistors. The proposed configuration exhibits high-output impedance which is important for easy cascading in the current-mode operations. The proposed circuit can be used as either a two-input three-output circuit or a three-input single-output circuit. In the operation of two-input three-output circuit, the bandpass, highpass, and bandreject filtering responses can be realized simultaneously while the allpass filtering response can be easily obtained by connecting appropriated output current directly without using additional stages. In the operation of three-input single-output circuit, all five generic filtering functions can be easily realized by selecting different three-input current signals. The filter permits orthogonal controllability of the quality factor and resonance angular frequency, and no inverting-type input current signals are imposed. All the passive and active sensitivities are low. Postlayout simulations were carried out to verify the functionality of the design