A Low-Power Mixed-Mode SIMO Universal Gm–C Filter

This paper describes a new single-input multiple-output (SIMO) mixed-mode universal biquad [Formula: see text]–[Formula: see text] filter. It can realize all kinds of filter responses including high-pass, band-pass, low-pass, band-stop and all-pass filters, simultaneously. Moreover, in this structure, all of these filters in all states of voltage mode, current mode, transresistance mode and transconductance mode are achieved by the same topology without any convertor. The proposed filter employs three operational transconductance amplifiers (OTAs) with four inputs and one output, three fully differential OTAs and two grounded capacitors. In other words, this filter is composed of six [Formula: see text] blocks and two grounded capacitors. The grounded capacitors are suitable for integrated circuit implementation. In order to reduce the power consumption, the OTAs are biased in subthreshold region. In addition, sensitivity analysis is included to show the low active and passive sensitivity performances of the filter. This filter is designed and simulated in HSPICE with 0.18[Formula: see text][Formula: see text]m model CMOS technology parameters. The simulation results show that the filter consumes only 75[Formula: see text][Formula: see text]W and operates at 1.5[Formula: see text]MHz with [Formula: see text]0.5[Formula: see text]V supply voltages and capacitors [Formula: see text][Formula: see text]pF.

VERSATILE TRANSADMITTANCE-MODE OTA-C UNIVERSAL BIQUAD FILTER USING MINIMUM COMPONENTS WITH INDEPENDENTLY ELECTRONIC TUNABILITY

This paper presents a transadmittance-mode (TAM) universal biquad filter with independently electronic tunability. The proposed biquad filter only employs three operational transconductance amplifiers (OTAs) and two grounded capacitors which are the minimum components count necessary for realizing independently electronic tunability of the parameters ω0 and ω0/Q without the need of control factors matching conditions. Moreover, the proposed circuit still achieves nearly all of the main advantages: (i) simultaneous realizations of universal filtering responses (low-pass, high-pass, band-pass, band-reject and all-pass) from the same topology, (ii) versatile input/output functions, (iii) orthogonally electronic tunability of the parameters ω0 and Q without the need of control factors matching conditions, (iv) no need of any resistors, (v) cascadable feature for all input and output terminals, (vi) no need of extra inverting or non-inverting amplifiers, (vii) the employment of only grounded capacitors, (viii) no component-value constraints (except for allpass filter function) and (ix) low active and passive sensitivity performances. H-spice simulations with TSMC 0.35 μm 2P4M CMOS process technology validate theoretical predictions.

Dual-Mode Quadrature Oscillator Using Current Follower Transconductance Amplifiers for GMI Sensors

For designing GMI sensors, realization of current/voltage-mode (dual-mode) quadrature sinusoidal oscillator with the employment of current follower transconductance amplifier (CFTA) as the active component is presented. The proposed circuit configuration comprising two CFTAs, one grounded resistor and two grounded capacitors can simultaneously provide two explicit quadrature output currents and two quadrature output voltages. Moreover, the proposed circuit topology enjoys the advantage of independent control of the condition of oscillation and frequency of oscillation and good active and passive sensitivity performances. The functionality of the proposed quadrature oscillators has been verified by PSPICE simulations.

VERSATILE VOLTAGE-MODE DDCC-BASED UNIVERSAL FILTER

A novel versatile three-input five-output universal voltage-mode filter employing two differential difference current conveyors, two grounded capacitors and three resistors is proposed. The proposed configuration can be used as either a single-input five-output or three-input two-output. Unlike the previously reported works, it can simultaneously realize five different generic signals: low-pass, band-pass, high-pass, notch and all-pass. Moreover, the proposed circuit still offers the following advantages: (i) the employment of two grounded capacitors, (ii) no need to employ inverting-type input signals, (iii) no need to impose component choice, (iv) orthogonal control of the resonance angular frequency ωo and the quality factor Q and (v) low active and passive sensitivity performances.

High-Input Impedance Voltage-Mode Multifunction Filter with Four Grounded Components and Only Two Plus-Type DDCCs

This paper introduces a novel voltage-mode multifunction biquadratic filter with single input and four outputs using two plus-type differential difference current conveyors (DDCCs) and four grounded passive components. The filter can realize inverting highpass, inverting bandpass, noninverting lowpass, and noninverting bandpass filter responses, simultaneously. It still maintains the following advantages: (i) using grounded capacitors attractive for integration and absorbing shunt parasitic capacitance, (ii) using grounded resistors at allXterminals of DDCCs suitable for the variations of filter parameters and absorbing series parasitic resistances at allXterminals of DDCCs, (iii) high-input impedance good for cascadability, (iv) no need to change the filter topology, (v) no need to component-matching conditions, (vi) low active and passive sensitivity performances, and (vii) simpler configuration due to the use of plus-type DDCCs only. HSPICE and MATLAB simulations results are provided to demonstrate the theoretical analysis.

VOLTAGE-MODE DDCC-BASED MULTIFUNCTION FILTERS

Two new voltage-mode multifunction biquadratic filter configurations were proposed. The first proposed high-input impedance multifunction filter with single input and four outputs, which can simultaneously realize voltage-mode low-pass, band-pass, and high-pass filter responses employing all grounded passive components. The second proposed configuration is a slight modification of the first proposed circuit. It leads two more notch and all-pass transfer functions than the first proposed circuit. Moreover, both the proposed circuits still offer the following advantages: (i) orthogonal control of ωo and Q, (ii) low active and passive sensitivity performances, (iii) simpler configuration due to the use of noninverting type differential difference current conveyors (DDCCs) only.

Inter-Trial Dynamics of Repeated Skilled Movements

In this paper, we develop a class of discrete dynamical systems for modeling repeated, goal-directed, kinematically redundant human movements. The approach is based on a mathematical definition of movement tasks in terms of goal functions. Each goal function can give rise to an associated goal equivalent manifold (GEM), which contains all body states that exactly satisfy the task requirements. A hierarchical control scheme involving in-trial action templates and inter-trial stochastic optimal error correction is included to generate a nonlinear map for the repeated execution of the task. A simple throwing task is used to illustrate the underlying concepts and to develop a model problem for further study. The performance at the goal level, as measured by the root mean square error, is shown to result from factors that are measures of passive sensitivity, the magnitude of body fluctuations, the orientation of fluctuations with the GEM, and the stability properties of the inter-trial controller. The action of the inter-trial controller developed for our model system is simulated and is shown to agree with the mathematically predicted performance.

NEW HIGH INPUT IMPEDANCE VOLTAGE-MODE LOWPASS, BANDPASS AND HIGHPASS FILTER USING CURRENT FEEDBACK AMPLIFIERS

A new high input impedance filter employing three current feedback amplifiers (CFAs) and six passive elements, three of them are grounded, is presented. The proposed circuit offers the following advantages: simultaneous realization of lowpass (LP), bandpass (BP) and highpass (HP) filtering functions, employs two grounded capacitors, exhibits high input and low output impedances which permits easy cascade connection, low passive sensitivity figures and orthogonal control of resonance frequency (ωo) and bandwidth (ωo/Q). PSPICE simulation results are given to verify the theoretical calculations.

A Minimum Component Grounded-Capacitor CFOA-Based RC Oscillator

A minimum-component grounded-capacitor single-frequency RC-sinusoidal oscillator circuit using the current feedback operational amplifier (CFOA) is presented. The circuit uses a single CFOA, two resistors, and two grounded capacitors. The circuit enjoys low active and passive sensitivity characteristics.