A Novel High-Pass Filters Implementation by Fully Differential Op Amp Integrators

2012 ◽  
Vol 229-231 ◽  
pp. 1531-1534
Author(s):  
Hai Dan Zhang ◽  
Hu Bao ◽  
Den Gan Chen ◽  
Jing Yu
Keyword(s):  
High Frequency ◽  
Circuit Complexity ◽  
Simulation Method ◽  
Signal Flow Graph ◽  
Fully Differential ◽  
Op Amp ◽  
Low Pass ◽  
Frequency Properties ◽  
High Pass ◽  
Excessive Noise

The design of low-pass and bandpass filters is often based on the leapfrog method which, in these cases, yields integrator-based structures. Using the leapfrog signal flow graph (SFG) for the simulation of high-pass filters leads to a differentiator-based structure which could be implemented by Gm-C or CCII conveniently. However, when we use Op amp RC integrators for good linearity, we have to use integrators, and not differentiators, for reasons related to the excessive noise behavior of the latter. This paper presents a new leapfrog SFG implementation by fully differential Op amp integrators, which combines good high-frequency properties with good noise properties. The direct SFG simulation method and single-ended output Op amp can also based on integrators, but all of them will lead to a relatively high circuit complexity and a high noise level. A design example is included, with comparisons of gain responses and noise densities.

scholarly journals Log-domain electronically-tuneable fully differential high order multi-function filter

2020 ◽  
Vol 10 (2) ◽  
pp. 1263
Author(s):  
Osama O. Fares
Keyword(s):  
Current Mode ◽  
Signal Flow Graph ◽  
Flow Graph ◽  
Signal Flow ◽  
Fully Differential ◽  
Low Pass ◽  
Band Pass ◽  
Simulation Results ◽  
Log Domain ◽  
High Pass

This paper presents the synthesis of fully deferential circuit that is capable of performing simultaneous high-pass, low-pass, and band-pass filtering in the log domain. The circuit utilizes modified Seevinck’s integrators in the current mode. The transfer function describing the filter is first presented in the form of a canonical signal flow graph through applying Mason’s gain formula. The resulting signal flow graph consists of summing points and pick-off points associated with current mode integrators within unity-gain negative feedback loops. The summing points and the pick-off points are then synthesized as simple nodes and current mirrors, respectively. A new fully differential current-mode integrator circuit is proposed to realize the integration operation. The proposed integrator uses grounded capacitors with no resistors and can be adjusted to work as either lossless or lossy integrator via tuneable current sources. The gain and the cutoff frequency of the integrator are adjustable via biasing currents. Detailed design and simulation results of an example of a 5th order filter circuit is presented. The proposed circuit can perform simultaneously 5th order low-pass filtering, 5th order high-pass filtering, and 4th order band-pass filtering. The simulation is performed using Pspice with practical Infineon BFP649 BJT model. Simulation results show good matching with the target.

A NEW ELECTRONICALLY-TUNABLE ACTIVE-ONLY UNIVERSAL BIQUAD

2011 ◽  
Vol 20 (03) ◽  
pp. 549-555 ◽  
Author(s):  
A. K. SINGH ◽  
R. SENANI ◽  
D. R. BHASKAR ◽  
R. K. SHARMA
Keyword(s):  
Pass Band ◽  
Voltage Mode ◽  
Op Amp ◽  
Op Amps ◽  
Reasonable Number ◽  
Low Pass ◽  
Band Pass ◽  
Electronically Tunable ◽  
High Pass ◽  
Realization Condition

A number of configurations for realizing voltage-mode (VM) biquads using op-amps and OTAs have been presented in the literature, however, none of these provide the following desirable properties simultaneously: (i) realizability of all the five standard filters (namely; low pass, high pass, band pass, band stop and all pass), (ii) tunability of all the three filter parameters (namely; ω0, bandwidth or Q0 and gain) and (iii) not requiring any realization condition in any of the five filter responses. This paper presents a new configuration which does possess all the above mentioned desirable properties simultaneously while using only two internally-compensated type op-amps and a reasonable number of OTAs. The workability of the new configuration has been demonstrated by SPICE simulations based upon CMOS Op-amp and CMOS OTAs.

On a Design of Narrowband FIR Low-Pass Filters

2011 ◽  
pp. 2882-2887
Author(s):  
Gordana Jovanovic Dolecek ◽  
Javier Diaz Carmona
Keyword(s):  
Impulse Response ◽  
High Frequency ◽  
Digital Filters ◽  
Stop Band ◽  
Low Frequency ◽  
Pass Band ◽  
Low Pass ◽  
Frequency Components ◽  
Band Pass ◽  
High Pass

Stearns and David (1996) states that “for many diverse applications, information is now most conveniently recorded, transmitted, and stored in digital form, and as a result, digital signal processing (DSP) has become an exceptionally important modern tool.” Typical operation in DSP is digital filtering. Frequency selective digital filter is used to pass desired frequency components in a signal without distortion and to attenuate other frequency components (Smith, 2002; White, 2000). The pass-band is defined as the frequency range allowed to pass through the filter. The frequency band that lies within the filter stop-band is blocked by the filter and therefore eliminated from the output signal. The range of frequencies between the pass-band and the stop-band is called the transition band and for this region no filter specification is given. Digital filters can be characterized either in terms of the frequency response or the impulse response (Diniz, da Silva & Netto, 2002). Depending on its frequency characteristic, a digital filter is either low-pass, high-pass, band-pass, or band-stop filters. A low-pass (LP) filter passes low frequency components to the output, while eliminating high-frequency components. Conversely, the high-pass (HP) filter passes all high-frequency components and rejects all low-frequency components. The band-pass (BP) filter blocks both low- and high-frequency components while passing the intermediate range. The band-stop (BS) filter eliminates the intermediate band of frequencies while passing both low- and high-frequency components. In terms of their impulse responses digital filters are either infinite impulse response (IIR) or finite impulse response (FIR) digital filters. Each of four types of filters (LP, HP, BP, and BS) can be designed as an FIR or an IIR filter (Ifeachor & Jervis, 2001; Mitra, 2005; Oppenheim & Schafer, 1999).

scholarly journals Single Active Element Based Voltage-Mode Multifunction Filter

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Jitendra Mohan ◽  
Bhartendu Chaturvedi ◽  
Sudhanshu Maheshwari
Keyword(s):  
The Novel ◽  
Voltage Mode ◽  
Fully Differential ◽  
Low Pass ◽  
Generic Filter ◽  
Multifunction Filter ◽  
Single Input ◽  
Band Pass ◽  
The Subject ◽  
High Pass

The paper presents a new voltage-mode multifunction filter. The proposed filter employs single modified fully differential second generation current conveyor (FDCCII), two grounded capacitors, and three resistors. The proposed circuit enjoys the employment of two grounded capacitors (attractive for absorbing shunt parasitic capacitance and ideal for IC implementation). The proposed circuit provides all five generic filter responses (low pass (LP), high pass (HP), band pass (BP), notch (NH), and all pass (AP) filter responses) simultaneously with single input. The novel proposed filter has low active and passive sensitivities. A number of time domain and frequency domain simulation results depicted through PSPICE using 0.18 µm TSMC process parameters are included to validate the theory. The proposed circuit is expected to enhance the existing knowledge on the subject.

scholarly journals Eddy covariance carbonyl sulphide flux measurements with a quantum cascade laser absorption spectrometer

2016 ◽  
Author(s):  
Katharina Gerdel ◽  
Felix M. Spielmann ◽  
Albin Hammerle ◽  
Georg Wohlfahrt
Keyword(s):  
Eddy Covariance ◽  
High Frequency ◽  
Trace Gas ◽  
Quantum Cascade ◽  
Laser Absorption ◽  
Low Pass ◽  
Flux Measurements ◽  
Carbonyl Sulphide ◽  
High Pass ◽  
Processing Steps

Abstract. The trace gas carbonyl sulphide (COS) has lately received growing interest in the eddy covariance (EC) community due to its potential to serve as an independent approach for constraining gross primary production and canopy stomatal conductance. Thanks to recent developments of fast-response high-precision trace gas analysers (e.g. quantum cascade laser absorption spectrometers (QCLAS)), a handful of EC COS flux measurements have been published since 2013. To date, however, a thorough methodological characterisation of QCLAS with regard to the requirements of the EC technique and the necessary processing steps has not been conducted. The objective of this study is to provide for the first time a rigorous analysis of the most widely used QCLAS model for making defensible EC COS flux measurements. Data were collected from May to October 2015 at a temperate mountain grassland in Tyrol, Austria. Analysis of the Allan variance of high-frequency concentration measurements revealed laser drift to occur under field conditions after an averaging time of around 50 s. We thus explored the use of two high-pass filtering approaches (linear detrending and recursive filtering) as opposed to block averaging for covariance computation. Spectral analysis revealed considerable noise at higher frequencies, appearing to influence the high-frequency region of co-spectra (and therefore covariances). By applying a finite-impulse response filter we removed the noise-affected spectral region. The effects of this digital high- and low-pass filtering, and additional low-pass filtering due to the eddy covariance system design, were corrected for using a site-specific reference model co-spectrum and a series of transfer functions. An independent validation of these post-processing steps was achieved by comparison of the CO2 and H2O flux measurements obtained with the QCLAS against those obtained with a closed-path infrared gas analyser. While the validation showed good correspondence and minor statistical differences between the three different high-pass filtering approaches – the benefits of high pass filtering clearly emerged as a reduction of the random flux uncertainty and a higher fraction of data passing the applied QA/QC criterions. We conclude that the most widely used QCLAS can be used to make defensible COS flux measurements provided the appropriate corrections are applied.

scholarly journals Akuisisi Data Sinyal Photoplethysmograph (PPG) Menggunakan Photodioda

2016 ◽  
Vol 2 (2) ◽  
pp. 32-41
Author(s):  
Putri Madona
Keyword(s):  
Analog To Digital Converter ◽  
Digital Converter ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Analog To Digital ◽  
Op Amp ◽  
High Pass Filter ◽  
Low Pass ◽  
Data Error ◽  
High Pass

Photoplethysmograph (PPG) merupakan metode yang digunakan untuk mengetahui kondisi sistem kardiovaskular dengan mengukur perubahan volume darah pada jaringan kulit. Dalam penerapannya, metode ini menggunakan sensor optik untuk menangkap sinyal elektrik yang berasal dari sumber cahaya yang terpantul karena perubahan aliran darah selama jantung bekerja. Pada proyek akhir ini dirancang sebuah alat yang mampu merepresentasikan aliran darah tubuh sebagai sinyal PPG dengan menggunakan photodioda sebagai sensor optik untuk menangkap cahaya dari LED Inframerah. Sinyal yang dihasilkan oleh photodioda adalah sinyal alami dari tubuh dengan frekuensi kecil yang bercampur dengan noise. Sinyal ini harus diproses secara rangkaian menggunakan rangkaian pengkondisi sinyal. Rangkaian pengkondisian sinyal yang digunakan adalah high pass filter, penguat op-amp, low pass filter dan adder. Pada proyek akhir ini sinyal PPG yang difilter berada pada frekuensi 0,05 Hz – 20 Hz sesuai dengan teori yang dinyatakan oleh referensi. Sinyal output yang diperoleh berupa sinyal analog. Agar dapat diolah dimikrokontroler diperlukan ADC (Analog to Digital Converter) untuk mengubah sinyal analog menjadi sinyal digital melalui program yang dimasukkan ke mikrokontroler. Data hasil akuisisi sinyal PPG oleh mikrokontroler kemudian ditampilkan pada LCD. Pengujian alat menunjukkan bahwa sistem yang dibuat telah mampu memperoleh dan menampilkan sinyal PPG namun ketidakstabilan yang muncul mengganggu output rangkaian (sinyal PPG) sehingga menyebabkan adanya data error pada data hasil akuisisi sinyal PPG.

A New Versatile Universal Biquad Configuration for Emerging Signal Processing Applications

2018 ◽  
Vol 27 (12) ◽  
pp. 1850196 ◽  
Author(s):  
Bhartendu Chaturvedi ◽  
Jitendra Mohan ◽  
Atul Kumar
Keyword(s):  
Second Generation ◽  
Current Mode ◽  
Pass Band ◽  
Current Conveyors ◽  
Fully Differential ◽  
Input Matching ◽  
Low Pass ◽  
Single Input ◽  
Band Pass ◽  
High Pass

The paper introduces a new versatile universal biquadratic configuration based on two fully differential second generation current conveyors without need of input matching conditions. The proposed circuit consists of two fully differential second generation current conveyors, four resistors and two grounded capacitors. The proposed biquad configuration provides all five standard filtering responses: low-pass, high-pass, band-pass, band-reject and all-pass in voltage-mode, transadmittance-mode, current-mode and transimpedance-mode. The proposed circuit is single-input multiple-outputs type, so all responses are available simultaneously. Moreover, extra inverting amplifier and double-type amplifier are also not required in the proposed circuit for any filtering response. The nonideal and parasitic effects of fully differential second generation current conveyor on the proposed circuit have also been investigated. HSPICE simulation results have been incorporated to validate the proposal.

scholarly journals Single-input Multiple-output Signals Third-order Active-R Filter for different Circuit Merit Factor (Q)

2015 ◽  
Vol 12 (3) ◽  
pp. 611-618
Author(s):  
Baghdad Science Journal
Keyword(s):  
Stop Band ◽  
Pass Band ◽  
Third Order ◽  
Op Amp ◽  
Merit Factor ◽  
Input Multiple Output ◽  
Low Pass ◽  
Single Input ◽  
Band Pass ◽  
High Pass

Single-input Multiple-output Signals Third-order Active-R Filter for different Circuit Merit Factor Q Configuration is proposed. This paper discusses a new configuration to realize third-order low pass, band pass and high pass. The presented circuit uses Single-input Multiple-output signals, OP-AMP and passive components. This filter is useful for high frequency operation, monolithic IC implementation and it is easy to design .This circuit gives three filter functions low-pass, high-pass and band-pass. This filter circuit can be used for different merit factor (Q) with high pass band gain. This gives better stop-band attenuation and sharper cut-off at the edge of the pass-band. Thus the response shows wider pass-band. The Ideal value of this filter circuit which is closed to Ideal value of third-order active-R filter is at 0.8? Q ?6. The advantages of this circuit are reduction in size and weight, increased circuit reliability, more economical and easy for manufacturing.

GROUNDED CAPACITOR FIRST-ORDER FILTERS INCLUDING CANONICAL FORMS

2006 ◽  
Vol 15 (02) ◽  
pp. 289-300 ◽  
Author(s):  
SUDHANSHU MAHESHWARI ◽  
IQBAL A. KHAN ◽  
JITENDRA MOHAN
Keyword(s):  
Computer Simulation ◽  
Input Voltage ◽  
Current Conveyor ◽  
Canonical Forms ◽  
First Order ◽  
Fully Differential ◽  
Low Pass ◽  
Simulation Results ◽  
Output Stages ◽  
High Pass

Six novel first-order filters with voltage input, voltage and current outputs employing a single fully differential current conveyor are proposed, three of which are canonical. All the circuits employ a grounded capacitor; and realize all-pass, low-pass and/or high-pass functions. Some circuits provide five distinct first-order functions or six functions with additional output stages. The proposed circuits are verified through computer simulation results.

Differential Filtering of Two Presynaptic Depression Mechanisms

2001 ◽  
Vol 13 (1) ◽  
pp. 69-85 ◽  
Author(s):  
Richard Bertram
Keyword(s):  
G Protein ◽  
High Frequency ◽  
Computational Models ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Protein Inhibition ◽  
Input Signals ◽  
Low Pass ◽  
High Pass ◽  
Impulse Train

The filtering of input signals carried out at synapses is key to the information processing performed by networks of neurons. Two forms of presynaptic depression, vesicle depletion and G-protein inhibition of Ca2+ channels, can play important roles in the presynaptic processing of information. Using computational models, we demonstrate that these two forms of depression filter information in very different ways. G- protein inhibition acts as a high-pass filter, preferentially transmitting high-frequency input signals to the postsynaptic cell, while vesicle depletion acts as a low-pass filter. We examine how these forms of depression separately and together affect the steady-state postsynaptic responses to trains of stimuli over a range of frequencies. Finally, we demonstrate how differential filtering permits the multiplexing of information within a single impulse train.

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