DVCC+ Based Immittance Function Simulators Including Grounded Passive Elements Only

Eight new immittance function simulators (IFSs) with only grounded passive elements are proposed in this paper. All of the IFSs consist of only two DVCC+s and a minimum number of passive components without needing any passive element matching constraints. Each of the proposed IFSs can provide one of [Formula: see text]L with series [Formula: see text]R and [Formula: see text]L with parallel [Formula: see text]R. As an application example, a second-order mixed-mode (MM) multifunction filter is developed from the proposed +L with series +R and +L with parallel +R. Furthermore, a proportional integral derivative (PID) controller is derived from the proposed +L with series +R. Many simulation results through the SPICE program and several experimental ones are included to verify the theory.

Novel Multifunction Filter using Current Feedback Amplifier

One configuration for realizing voltage- mode multifunction filters using current feedback amplifiers (CFOA) is presented. The proposed voltage -mode circuit exhibit simultaneously low pass and band pass filters. The proposed circuits offer the following features: No requirements for component matching conditions; low active and passive sensitivities; employing only grounded capacitors and the ability to obtain multifunction filters from the same circuit configuration.

Improved Electronically-Tunable Current-Mode Square-Root-Domain First-Order Multifunction Filter

Some time back, Kircay reported an electronically-tunable current-mode square-root-domain first-order filter capable of realizing low-pass (LP), high-pass (HP) and all-pass (AP) filter functions. When simulated in SPICE, Kircay’s circuit has been found to exhibit DC offsets in case of LP and AP responses and incorrect transient response in case of HP response. In this paper, an improved circuit overcoming these difficulties/deficiencies has been suggested and its workability of the improved circuit as well as its capability in meeting the intended objectives has been demonstrated by SPICE simulation results.

High-Input Impedance Voltage-Mode Multifunction Filter

This paper proposes a high-input impedance voltage-mode (VM) multifunction biquad filter which employs three current-feedback amplifiers (CFAs), three resistors, and two grounded capacitors. The proposed VM multifunction biquad filter has single-input and triple-output and can realize non-inverting low-pass (NLP), inverting band-pass (IBP), and non-inverting band-stop (NBS) voltage responses at the same time without increasing component selection. The proposed VM multifunction biquad filter enjoys the orthogonal tunability of angular frequency and quality factor and also provides the advantage of using only two grounded capacitors, high-input impedance and low active/passive sensitivity. The performance of the proposed VM multifunction biquad filter is verified through its hardware implementation and OrCAD PSpice simulation based on AD844-type CFAs. The circuit analysis, sensitivity analysis, and NLP, IBP, and NBS voltage responses are also shown in this paper. The paper presents a method to effectively reduce the active and passive components, maintain good circuit performance, and reduce circuit costs.

Dual-mode multifunction filter realized with a single voltage differencing gain amplifier (VDGA)

This article presents the dual-mode multifunction biquad filter realized employing only a single voltage differencing gain amplifier (VDGA), one resistor and three capacitors. The proposed filterwith one input and three outputs can configure as voltage-mode or current-mode filter circuit with the appropriate input injection choice. It can also synthesis the three standard filter functions, which are highpass, bandpass, and lowpass responses without modifying the circuit configuration. Orthogonal adjustment between the natural angular frequency (o) and the quality factor (Q) of the filter is achieved. Detail analysis of non-ideal VDGA effects and circuit component sensitivity are included. The circuit principle is verified by means of simulation results with TSMC 0.35-m CMOS process parameters.