Current Mode Biquad Filter with Minimum Component Count

A low power current controllable single-input three-output current-mode filter using MOS transistors only

A new MOS-C multifunction filter and its third order oscillator application

In this paper, a new circuit based on single voltage differencing trans-conductance amplifier (VDTA) is presented which realizes band pass (BP) and high pass (HP) filtering functions in trans-admittance-mode (TAM). In addition of single VDTA as active element, it also consists of two grounded capacitors and one resistor as three passive elements. Moreover, the proposed circuit can be operated at low voltage (±1V) power supply which results low power consumption. The circuit also exhibits low active and passive sensitivity. The validity of proposed filter is verified in CMOS technology through PSPICE simulation.

A new resistorless single-input-multi-output (SIMO) universal transadmittance (TA) type filter employing two voltage differencing transconductance amplifiers (VDTA) and two grounded capacitors is proposed. The proposed topology realizes simultaneously low pass (LP), high pass (HP), and band pass (BP) filter functions. Band rejects (BR) and all pass (AP) filters are also realizable through appropriate connections of currents. The proposed configuration also offers independent control of natural angular frequency (ω 0) and bandwidth (BW) and low active and passive sensitivities. The workability of proposed configuration has been demonstrated through PSPICE simulations with TSMC CMOS 0.18 μm process parameters.

In this paper, a new current-mode (CM) Kerwin-Huelsman-Newcomb ( KHN) biquad is proposed which is suitable for crossover networks. The proposed circuit employs three differential voltage current conveyors (DVCCs) as active elements together with two capacitors and four resistors as passive elements, which all are grounded. The circuit simultaneously provides the three basic filter functions, namely band pass (BP), high pass (HP) and low pass (LP) functions. TSPICE simulations are performed on employing CMOS Technology 2mum process and the performance simulation results is tested by comparing with the theoretical results of the filter.

This paper presents a novel One-shot pulse Generator Circuit, which is composed of only one differential voltage current conveyor (DVCC) as the active element. The application circuits utilizing the DVCC are introduced and implemented. Only one DVCC and two resistors and one capacitor are required to construct every circuit. Each circuit is able to provide a pulse-shaped response having changeable width via a positive-edge triggered signal. The first one is a general one-shot pulse generating circuit. The second design can reduce the recovery time after applying triggered signals. Is-Spice is the simulation software to simulate every model. To fabricate the models commercially available ICs (AD844AN) and passive elements are required. Program and experimental outputs satisfy theoretical results.

Fractional-order filter employing two differential voltage current conveyors, four grounded passive elements, one of which has fractional-order impedance, is presented. The filter provides low-pass and band-pass transfer function simultaneously and its order can be set between one and two. Relations and recommendations for determining the passive element parameters are given. PSpice simulations confirm the theoretical expectations, show very good performance with AD844 amplifier as conveyor replacement, and discover the most critical parasitic properties of conveyors.

The four terminal Current feedback op-amps (CFOA) with an external compensation pin, such as AD844, have received prominent attention during the past decade as alternative building blocks for analog circuit design because of their significant advantages over the traditional voltage-mode op-amp (VOA). A popular application of CFOAs has been in realizing voltage-mode (VM) and current-mode (CM) biquad filters. Previously known universal CM biquads (i.e. those capable of realizing all the five generic filter functions namely, low-pass, band-pass, high-pass, notch and all-pass) realizable with CFOAs require two to nine CFOAs. Although a few dual-function/three-function single-CFOA-based CM circuits have appeared in literature, no single-CFOA-based canonic universal CM biquad with explicit CM output has been reported in the literature up until now. This paper fills this void by presenting a set of eight minimal universal CM biquads all of which are realizable with only a single CFOA. The non-ideal analysis of the proposed circuits has been presented, their comparative features, advantages and limitations have been brought out. The workability of all the proposed circuits has been confirmed by PSPICE simulations and experimental results based upon AD844 type CFOAs.

The design of transconductance-mode multifunction biquad filter containing three input voltage nodes and single-output current node is proposed. Its circuit principle is emphasized on employing Voltage Differencing Current Conveyor (VDCC) to be an active building block. The proposed filter description uses three VDCCs co-working with two grounded capacitors and three grounded resistors. The synthesis of the proposed multifunction filter is based on avoidance of using multiple-output active elements to achieve commercially available integrated circuits for practical implementation. Additionally, without multiple-output active element, it can alleviate current tracking error from the current mirrors used in output ports. It also decreases the amounts of the transistors inside the active elements. The proposed multifunction filter offers all 5 filter functions, which are non-inverting Low-Pass (LP), non-inverting High-Pass (HP), non-inverting Band-Pass (BP), non-inverting Band-Reject (BR) and also non-inverting All-Pass (AP) functions from same circuit topology under different circuit condition for input signals. Furthermore, the natural frequency for all filtering responses is independently achieved from the bandwidth or the quality factor of the proposed filter. For cascade-able connectivity, the output current port indeed provides a high impedance. In addition, the magnitude of the output current for all filtering functions can be resistively adjusted. The consideration for non-ideal case of the presented multifunction filter is also analyzed. The simulation and experimental results of the presented transconductance multifunction biquad filter based on VDCC practically implemented by the commercially available ICs, LM13700 and AD844 can validate the theoretical anticipation.

Design and implementation of monostable multivibrators employing differential voltage current conveyors

Multiple-input single-output low-input and high-output impedance current-mode biquadratic filter employing five modified CFTAs and only two grounded capacitors

In this article a new electronically controllable grounded frequency-dependent negative resistance (FDNR) simulation circuit is proposed. The presented circuit employs two voltage differencing current conveyors (VDCCs), two grounded capacitances and one grounded resistance. The proposed configuration simulates a grounded FDNR without any requirement of component matching and enjoys the electronic control through transconductances of VDCCs. The presented circuit exhibit excellent non-ideal behavior and low values of sensitivity figures. The high frequency limitation of realized configuration has been evaluated under the influence of parasitic impedances. The workability of the proposed FDNR has been confirmed by SPICE simulations using CMOS VDCC.

A new versatile voltage-mode multifunction biquadratic filter with three inputs and four outputs is proposed. The proposed configuration employs two differential voltage current conveyors (DVCCs) as active elements together with two grounded capacitors and two resistors as passive elements. The circuit can act as a multifunction voltage-mode filter with two inputs and four outputs and can perform simultaneous realization of voltage-mode bandreject, highpass, bandpass and lowpass filter signals from the four output terminals, respectively, without any component choice conditions. On the other hand, it also can act as a universal voltage-mode filter with three inputs and a single output and can realize five generic voltage-mode filter signals from the same configuration without any component matching conditions. HSPICE and MATLAB simulations results are provided to demonstrate the theoretical analysis.

This research paper contains a new electronically tunable current-mode biquadratic universal filter using a new active building block; current controlled differential difference current conveyor transconductance amplifier (CCDDCCTA). The proposed filter provides the following important and desirable features: (i) One can use only one CCDDCCTA and two capacitors; (ii) One can get low pass (LP), band pass (BP), high pass (HP), notch (NF) and all pass (AP) current responses from the same configuration without any alteration; (iii) Passive components are grounded, which ease the integrated circuit implementation; (iv) Responses are electronically tunable; and (v) Sensitivity is low. Moreover, the non-ideality analysis shows that the parasitic passive components can be compensated for the proposed circuit. The functionality of the design is verified through SPICE simulations using 0.25 μm CMOS TSMC technology process parameters. Simulation result agrees well with the theoretical analysis.

In this work, a novel voltage-mode (VM) single-input four-output universal filter topology is presented. The proposed structure uses two resistors, two capacitors and only one voltage differencing current conveyor (VDCC) and generates all biquadratic filtering functions namely: low-pass (LP), band-pass (BP), high-pass (HP) and band-reject (BR). The quality factor and natural frequency of the filter can be adjusted electronically without changing the values of the passive components. Moreover, the circuit does not require any condition of component matching and has a good sensitivity performance with respect to tracking errors of passive components and the active parameter. PSpice simulation results confirm the results of the theoretical analysis.