This brief presents a comprehensive study on a particular kind of conveyor called second-generation voltage conveyor (VCII). This building block is based on voltage conveying concept and is the dual ...of second generation current conveyor (CCII). It is shown that VCII is a very useful block in those configurations where CCII is limited, in terms of number of active blocks. The results of this brief are helpful in choosing the best building block between CCII and VCII for each specific application. Finally, for the first time, the CMOS implementation of VCII is also presented. Simulation results with PSPICE using 0.35-μm CMOS technology and supply voltage of ±1.65 V are given to approve the theory.
In this brief, a new circuit topology to realize an electronically tunable grounded capacitor multiplier with extremely low power consumption and low supply voltage requirement is investigated. The ...proposed circuit uses an electronically tunable second generation voltage conveyor (VCII) and a single floating capacitor. Owing to the translinear principle, current gain of VCII is varied through a control current and, as a result, the value of simulated capacitor is also varied. Favorably the obtained gain is temperature insensitive. Both of the required supply voltage and control currents are very low because all transistors are biased in subthreshold region: therefore, electronic tunability is achieved while the power consumption is kept at very low value. In addition, the circuit realization is very simple since only twelve transistors are required. Simulation results, performed at schematic level in 0.18 μm CMOS technology and supply voltage of ±0.3V, are presented. It is shown that a multiplication factor from 1 to 100 is possible while the power consumption varies from 10 nW to 67 nW.
A new low-voltage low-power class-AB second generation voltage conveyor (VCII) is presented. The proposed circuit is based on an improved class-AB flipped voltage follower (FVF) designed by adding a ...simple negative feedback loop to the conventional class-AB circuit. This modification ensures high current drive capability of at least 2 mA for both falling and rising edges of input signal along with very low 2-mΩ output impedance and high accuracy. Benefiting from the new class-AB FVF, the proposed VCII features a very simple implementation, extremely low impedance at Y and Z terminals (2 mQ), high impedance at X terminal (370 kQ) and high accuracy in current and voltage conveying (99% and 98%, respectively). Moreover, it exhibits current drive capability 117.6 times larger than its bias current (17 μA). The circuit occupies 381.5 μm × 197 μm area. The application of the proposed VCII as a voltage integrator is also presented. Simulation results using PSpice and 0.35-μm CMOS technology with ±1.65-V supply voltage are provided to demonstrate the presented theory. A comparison with the literature is also provided.
•The anemometer is realized with a solid sphere structure of 7 cm diameter.•It is provided of two cylindrical sectional channels of 6 mm in diameter.•The wind channels do not intersect and are ...orthogonal to each other, so providing the x and y axes of the local coordinates.
We present a novel anemometric system, which could be also suitable for IC integration with MEMS technology. The proposed approach is illustrated at both the design and implementation level, and it allows reliable absolute and relative wind measurement to be obtained for both fixed point or moving vehicles, for instance, on boats. The solution here represents a low-cost, low-power, portable measuring system. The prototype makes use of a fully 3D-printable spherical structure, that acts as an air conveyor, and a differential pressure measuring technique. A preliminary feasibility study has been conducted, strengthened by computational fluid dynamic simulations, and the following measurements on the prototype that has been fabricated have shown promising results. As a result, the test campaign on the prototype has allowed to obtain reliable performance on the wind speed measurement in the range 0–20 m/s and a directional measuring range of 306° with a precision of about ±2.5% and ±3.5% for the wind speed and wind angle, respectively.
Capacitive multipliers have found wide applications in capacitive interfaces and other analog circuits requiring large value capacitors. Recently a new active building block (ABB) called second ...generation voltage conveyor (VCII) has been proved to be useful in many analog signal processing applications. Due to the interesting features offered by VCII, in this paper a new VCII based implementation of grounded capacitance multiplier is proposed employing two VCIIs, two resistors and one grounded capacitor. The circuit can produce both positive and negative multiplication factors in a range of −50 to +50. Its main features are wide frequency range, high resolution, low series resistance, simple structure, low power consumption and maximum percentage error of 7.8%. The circuit enjoys high frequency range up to 10 MHz, even if it employs a floating capacitor in its structure. The behavior of the proposed circuit is analysed by taking into account also the effects of VCII parasitic elements and non-ideal gains. SPICE simulation results using a 0.35 µm CMOS technology parameters are reported. The proposed circuit has been also experimentally tested by using AD844 as VCII. Measurement results on the standalone capacitance multiplier have shown a mean percentage error of 9% across the entire gain range. Finally, the application of the proposed circuit in realizing a low pass filter is also presented to demonstrate the proposed circuit feasibility.
Class AB tunable active inductor Pantoli, L; Stornelli, V; Leuzzi, G
Electronics letters,
01/2015, Letnik:
51, Številka:
1
Journal Article
Recenzirano
A class AB active inductor with high linearity, including a minimum number of components, is presented. Class AB operation is absent from the literature on the design of active inductors but is ...addressed in this reported work. Circuit details are given. A prototype board on a TLX8 substrate has been fabricated and tested showing the circuit feasibility for use in many commercial market applications, as integrated circuits, or discrete filters and oscillators.
•A novel anemometric system based on a hot film sensor array is proposed.•Modified Wheatstone bridge sensor interface with auto-balancing capability.•Wind direction and speed measurement capability ...with 0.6m/s sensitivity.•CMOS 0.35μm architecture of the full system is presented.
In this paper we present a novel complete anemometric electronic system based on an array of hot wire sensors, provided by Telecontrolli SME, and a suitable heater feedback that achieves, thanks to a dedicated algorithm, a CMOS integrable portable solution showing a robust design, without moving parts and small dimensions. The sensor interface is implemented by means of a modified Wheatstone bridge architecture with autobalancing capability. Comparisons with a commercial cup anemometer have shown that the proposed architecture, with reduced space occupancy and low power consumption, is suitable to operate in a natural environment in the −20 to +55°C temperature range providing wind speed and direction measurement. Concerning the wind speed, a 0.6m/s sensitivity has been achieved. The integrated CMOS design of the final system is also presented and discussed in the paper.
A low-noise tunable filter with high dynamic range and minimum power consumption is presented and addressed with circuit details. It is based on an active solution simulating an inductive behaviour ...that allows improving the filter quality factor without affecting the noise performance. The low-order bandpass filter is realised with minimum number of components and it is suitable to be integrated in integrated circuit or used in hybrid transceiver and modern reconfigurable radio systems. A prototype board with discrete components has been fabricated and tested with good results.
Recently, second generation voltage conveyor (VCII)-based transimpedance amplifiers (TIAs) have begun to find their way in different applications, among which, silicon photomultipliers (SiPMs) ...interfacing circuitry. There are many advantages which make VCII-based TIAs attractive over conventional circuits: the intrinsic low impedance at VCII current input Y port is very helpful to mitigate the effect of high value sensor capacitance and provides fast response time; the achieved bandwidth is high and due to current mode operation; the circuits enjoy the low-voltage low-power features. As signal-to-noise ratio is a crucial parameter in SiPMs interface circuit applications, here we consider the noise specifications and optimization of VCII-based SiPM interface circuits. The noise model of VCII is introduced and equivalent noise of a VCII-based interface circuit is derived. Methods to optimize trade-offs existing between key parameters including power consumption, gain and noise performance are discussed. Simulation results are also provided showing a considerable reduction of two orders of magnitude in most of the noise performances when compared to the previous work while preserving other performance parameters.
In this letter we propose a novel low voltage and low power single-CCII bootstrap circuit specifically designed to be implemented as input stage in ElectroCardioGraphy (
ECG
) or ...ElectroEncephaloGraphy (
EEG
) acquisition systems. The proposed circuit implements only a second generation current conveyor that has been designed to obtain, at X and Z nodes, reduced parasitic impedances, so improving CCII performance. Moreover, simulation results are also presented for a two electrodes
ECG
system. The circuit, designed in a standard 0.35 μm CMOS technology, shows low voltage (1.5 V) low power (28 μW) characteristics, so it is particularly suitable for portable applications.
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