Transimpedance Mode Research Articles

Single EX-CCCII-Based First-Order Versatile Active Filter

This paper presents a new current-mode first-order versatile active filter employing one extra-x second-generation current controlled current conveyor (EX-CCCII) and one grounded capacitor. The proposed filter can realize first-order filtering functions of a low-pass filter (LPF), high-pass filter (HPF), and all-pass filter (APF) within the same topology with low-input and high-output impedances required for current-mode circuits. This multiple-output EX-CCCII-based filter can provide six transfer functions as both non-inverting and inverting filtering functions of the LPF, HPF, and APF are obtained. The filter also offers electronic control of the pole frequency of all filtering. The proposed current-mode filter can be applied to work as a mixed-mode active filter, namely in the transadmittance-mode (TAM), transimpedance-mode (TIM), and voltage-mode (VM). Each operation mode can provide six transfer functions. The proposed filter was simulated and designed using SPICE and 0.18 µm CMOS technology. Experimental results using the commercially available integrated circuit AD844 were used to confirm the functionality of the new circuits.

Design of Mixed-Mode Analog PID Controller with CFOAs.

The design of a mixed-mode proportional-integral-derivative (PID) controller circuit using current-feedback operational amplifiers (CFOAs) as active components is proposed. With the same circuit topology, the proposed configuration of three CFOAs, four resistors, and two capacitors is capable of performing the PID controller in each of the following four modes: voltage mode, trans-admittance mode, current mode, and trans-impedance mode. Numerous mathematical analyses are conducted to determine the controller's performance under both ideal and non-ideal conditions. Additionally, the mixed-mode second-order lowpass filter is suggested and also used to examine the workability of the proposed mixed-mode PID controller in a feedback control structure. The proposed PID controller is implemented with the commercially available IC-type CFOA AD844, and the simulation results are presented to illustrate the functionality of the controller and its closed-loop control system. According to the findings, the total power consumption of the proposed PID controller is 0.348 W, with symmetrical supply voltages of ±9 V. It also has a temperature variation of less than 0.2% over the AD844's usable range. Monte Carlo statistical analysis results revealed that the gain responses of the controller exhibited a deviation of no more than 7.72% from the theoretical value. The controlled filter in a closed-loop control system has a 43% faster rise time and peak time than the uncontrolled filter in all four modes of operation. It also has a steady-state error less than 0.2 mV for voltage responses and 0.72 µA for current responses.

Current-mode PID controllers employing commercially available active components

This work describes two current-mode (CM) PID controllers using only two commercially active components, namely, current feedback operational amplifier (CFOA), and four passive components, i.e. two capacitors and two resistors. They have appropriate output and input impedance values, allowing them to be utilized in cascade connections without requiring a buffer circuit. Since all capacitors are grounded, it is suitable for integrated circuit (IC) technology. Moreover, the controllers can be easily modified to operate in voltage-mode (VM), transimpedance-mode (TIM), and transadmittance-mode (TAM) PID controllers. Using 0.18 µm CMOS parameters and the PSPICE program, the proposed circuits are simulated to verify the theoretical behavior. To demonstrate the viability of the circuits, experimental tests using commercially available AD844 integrated circuits are performed. The suggested PID circuits are alsoexperimental tested in a closed-loop system as an example.

Single VDGA-Based Mixed-Mode Electronically Tunable First-Order Universal Filter.

This article presents a mixed-mode electronically tunable first-order universal filter configuration employing only one voltage differencing gain amplifier (VDGA), one capacitor, and one grounded resistor. With the appropriate selection of the input signals, the proposed circuit can realize all three first-order standard filter functions, namely low pass (LP), high pass (HP), and all pass (AP), in all four possible modes, including voltage mode (VM), trans-admittance mode (TAM), current mode (CM), and trans-impedance mode (TIM), from the same circuit structure. It also provides an electronic tuning of the pole frequency and the passband gain by varying transconductance values. Non-ideal and parasitic effect analyses of the proposed circuit were also carried out. PSPICE simulations and experimental findings have both confirmed the performance of the design. A number of simulations and experimental observations confirm the viability of the suggested configuration in practical applications.

Supplementary MOSFET-C transimpedance mode filters for wireless systems

Supplementary MOSFET-C transimpedance mode filters for wireless systems

Electronically Tunable Mixed Mode Universal Filter Employing Grounded Passive Components

A recently developed active element, namely Voltage Differencing Differential Voltage Current Conveyor (VD-DVCC), is employed in the design of electronically tunable mixed-mode universal filter. The filter provides low pass (LP), high pass (HP), band pass (BP), band reject (BR) and all pass (AP) responses in voltage-mode (VM), current-mode, trans-impedance-mode (TIM) and trans-admittance-mode (TAM). The filter employs two VD-DVCCs, three resistors and two capacitors. All the passive components employed are grounded. The attractive features of the filters include: (i) ability to operate in all four modes, (ii) use of grounded passive components, (iii) tunability of Q factor independent of pole frequency, (iv) high input impedance for VM and TIM mode, (v) high output impedance explicit current output for CM and TAM and (vi) no requirement for double/negative input signals (voltage/current) for response realization. The VD-DVCC is designed and validated in Cadence virtuoso using 0.18µm PDK at supply voltage of ±1V. The operation of filter is examined at 5.305 MHz frequency. The non-ideal gain and sensitivity analysis is also carried out to study the effect of process and components spread on the filter performance. The obtained results bear close resemblance with the theoretical findings.

Single VDGA-Based Mixed-Mode Universal Filter and Dual-Mode Quadrature Oscillator.

This article presents the circuit designs for a mixed-mode universal biquadratic filter and a dual-mode quadrature oscillator, both of which use a single voltage differencing gain amplifier (VDGA), one resistor, and two capacitors. The proposed circuit has the following performance characteristics: (i) simultaneous implementation of standard biquadratic filter functions with three inputs and two outputs in all four possible modes, namely, voltage-mode (VM), current-mode (CM), trans-admittance-mode (TAM), and trans-impedance-mode (TIM); (ii) electronic adjustment of the natural angular frequency and independently single-resistance controllable high-quality factor; (iii) performing a dual-mode quadrature oscillator with simultaneous voltage and current output responses; (iv) orthogonal resistive and/or electronic control of the oscillation condition and frequency; (v) employing all grounded passive components in the quadrature oscillator function; and (vi) simpler topology due to the use of a single VDGA. VDGA non-idealities and parasitic elements are also investigated and analyzed in terms of their influence on circuit performance. To prove the study hypotheses, computer simulations with TSMC 0.18 μm CMOS technology and experimental confirmatory testing with off-the-shelf integrated circuits LM13600 have been performed.

First order universal filters employing single DV-EXCCCII

ABSTRACT This paper reports two filter circuits based on Differential Voltage Extra-X Current Controlled Current Conveyor (DV-EXCCCII). The first proposed circuit is a voltage-mode first-order universal filter that employs one DV-EXCCCII, one resistor, and one grounded capacitor. This circuit can realise all standard first-order filters, that is, low-pass, high-pass and all-pass filter. The second proposed circuit is a first-order multimode universal filter that employs a single DV-EXCCCII. This circuit can realise filter in current-mode, voltage-mode and trans-admittance mode with a single capacitor. However, a trans-impedance mode universal filter is realised with an additional resistor. Furthermore, the filter is electronically tunable with the bias current of DV-EXCCCII. The proposed filter circuits are verified using the SPECTRE simulator of CADENCE VIRTUOSO tool in 0.18 µm UMC CMOS technology parameters.

1.2 V Differential Difference Transconductance Amplifier and Its Application in Mixed-Mode Universal Filter.

This paper presents a new mixed-mode universal filter based on a differential difference transconductance amplifier (DDTA). Unlike the conventional transconductance amplifier (TA), this DDTA has both advantages of the TA and the differential difference amplifier (DDA). The proposed filter can offer four-mode operations of second-order transfer functions into a single topology, namely, voltage-mode (VM), current-mode (CM), transadmittance-mode (TAM), and transimpedance-mode (TIM) transfer functions. Each operation mode offers five standard filtering responses; therefore, at least twenty filtering transfer functions can be obtained. For the filtering transfer functions, the matching conditions for the input and passive component are absent. The natural frequency and the quality factor can be set orthogonally and electronically controlled. The performance of the proposed topology was evaluated by PSPICE simulator using the 0.18 µm CMOS technology from the Taiwan Semiconductor Manufacturing Company (TSMC). The voltage supply was 1.2 V and the power dissipation of the DDTA was 66 µW. The workability of the filter was confirmed through experimental test by DDTA-based LM13600 discrete-component integrated circuits.

CFOA‐based simple mixed‐mode first‐order universal filter configurations

AbstractThis brief communication presents two current feedback op‐amp (CFOA)‐based simple first‐order mixed‐mode universal filter topologies—one of them providing first‐order low‐pass (LP), high pass (HP), and all pass (AP)—all the three filters in voltage‐mode (VM)/trans‐admittance‐mode (TAM) while the other one realizing the quoted three functions in current‐mode (CM)/trans‐impedance‐mode (TIM). Except the all pass filter realization from the first configuration which needs a second CFOA also as gain‐of‐two amplifier, in all the remaining cases of both the configurations, only a single CFOA is needed. The other notable features of the circuits are employment of only three resistors and a grounded capacitor (as preferred for IC implementation) and the availability of independent tunability of the gain (H0) and cut‐off frequency/pole frequency (ω0) of all the three filters, in both the cases. In spite of not offering ideally infinite input impedance in VM/TAM mode and ideally zero input impedance in CM/TIM mode, the circuits still possess easy cascadability due to providing a voltage output from a low‐output impedance terminal W while the current output from the high output impedance terminal Z. Non‐ideal and sensitivity analyses have also been carried out. The workability of the proposed circuits has been demonstrated through PSPICE simulations and experimental results using the commercially available AD844‐type IC CFOA.

Electronically tunable mixed-mode third-order universal filter using a single EX-CCCII

ABSTRACT A new Extra-X Current Controlled Conveyor (EX-CCCII) based electronically tunable mixed-mode third-order universal filter has been proposed, which is composed of a single EX-CCCII, three capacitors and a load resistor. The proposed circuit employs a least number of components and can operate in four possible modes of operation, namely voltage mode (VM), current mode (CM), transadmittance mode and transimpedance mode (TIM). Five possible filtering functions – low-pass, high-pass, band-reject, band-pas and all-pass are realised through suitable selection of input signals, operable in three modes (VM, CM and TIM). The angular frequency (ωo) of the proposed circuit is electronically tunable. Non-ideal effects and parasitic analysis is carried out. Exhaustive simulation results using ±0.5 V supply are included to support the present theory.

Voltage Differencing Buffered Amplifier-Based Novel Truly Mixed-Mode Biquadratic Universal Filter with Versatile Input/Output Features

In this paper, a first-of-a-kind mixed-mode universal filter employing three VDBAs and three passive components, is proposed. The filter operates in all four modes and provides all five filter responses, namely voltage-mode (VM), current-mode (CM), trans-impedance-mode (TIM), or trans-admittance-mode (TAM). Additionally, the same filter topology can also work as a CM single-input-multi-output (SIMO) filter. A state-of-the-art comparison of various ‘voltage differencing’ variants of the voltage differencing buffered amplifier (VDBA)-based SIMO/MISO (single-input-multi-output/multi-input-single-output)-type biquad filters further highlight the significance of the presented research. In the proposed no passive component matching is required for generating the filter responses. The filter circuit also provides inbuilt tunability of the quality factor independent of the pole frequency. The non-ideal frequency dependent gain and component sensitivity analyses of the filter were also performed. The Silterra Malaysia 0.18μm process design kit (PDK) is employed to design and validated the proposed VDBA-based filter using the Cadence design software. The simulation results closely follow the theoretical predictions. To further verify the practical feasibility of the proposed filter, an experimental evaluation is also completed. The VDBA-based filter is implemented using off-the-shelf operational transconductance amplifiers Intersil CA3080, Texas Instruments LF356 op-amp, and Analog Devices AD844s. The filter is designed for a characteristic frequency of 100 kHz. The time and frequency domain measurement results indicate the proper functioning of the filter.

Tunable Mixed-Mode Voltage Differencing Buffered Amplifier-Based Universal Filter with Independently High-Q Factor Controllability

This paper proposes the design of a mixed-mode universal biquad configuration, which realizes generic filter functions in all four possible modes, namely voltage mode (VM), current mode (CM), transadmittance mode (TAM), and transimpedance mode (TIM). The filter architecture employs two voltage differencing buffered amplifiers (VDBAs), two resistors and two capacitors, and can provide lowpass (LP), bandpass (BP), highpass (HP), bandstop (BS), and allpass (AP) biquadratic filtering responses without any circuit alteration. All passive elements used are grounded, except VM. The circuit not only allows for the electronic tuning of the natural angular frequency (ωo), but also achieves orthogonal tunability of the quality factor (Q). It also provides the feature of availability of output voltage at the low-output impedance terminal in VM and TIM, and does not require inverting-type or double-type input signals to realize all the responses. Moreover, in all modes of operation, the high-Q filter can be easily obtained by adjusting a single resistance value. Influences of the VDBA nonidealities and parasitic elements are also discussed in detail. PSPICE simulations with TSMC 0.18-µm CMOS process parameters and experimental testing results with commercially available IC LT1228s have been used to validate the theoretical predictions.

Electronically Tunable SIMO type Mixed-mode Biquadratic Filter using Single FTFNTA

In this manuscript, a new electronically tunable single input multiple output (SIMO) type mixed-mode biquad filter is proposed. It comprises of single Four Terminal Floating Nullor Transconductance Amplifier (FTFNTA) as an Active Building Block, one resistor, and two grounded capacitors. The proposed design can generate current mode (low-pass, high-pass, and band-pass) filters and transimpedance mode (band-pass and inverting low-pass) filters simultaneously for current as an input. Similarly, for voltage as input, it can generate voltage mode (high-pass and inverting band-pass) filters and transadmitance mode (inverting band-pass and inverting high-pass) filters simultaneously. The pole frequency (ω 0 ) and quality factor (Q 0 ) can be tuned electronically as well as through a grounded capacitor without disturbing the bandwidth (ω 0 /Q 0 ). Design is independent from the input as well as passive component matching constraint. The presence of grounded capacitors makes the circuit feasible for IC realization. The functionality of the proposed design is validated through PSIPCE simulation. To check the robustness of the proposed design Monte Carlo, sensitivity, and noise analysis is also performed.

New Electronically Tunable Third Order Filters and Dual Mode Sinusoidal Oscillator Using VDTAs and Grounded Capacitors

This study introduces a third order filter and a third order oscillator configuration. Both the circuits use two voltage difference transconductance amplifiers (VDTAs) and three grounded capacitors. By selecting the input and output terminals properly, current mode and transimpedance mode low-pass and band-pass filters can be obtained without component matching conditions. The natural frequency (ω0) can be tuned electronically. The oscillator circuit provides voltage and current outputs explicitly. The condition of oscillation (CO) and the frequency of oscillation (FO) can be adjusted orthogonally and electronically. The workability of the configurations is judged using TSMC CMOS 0.18 μm technology parameter as well as commercially available LM13700 integrated circuits (ICs). The simulation results show that: for ±0.9V power supply, the power consumption is 1.08 mW for both the configurations, while total harmonic distortions (THDs) are less than 2.06% and 2.17% for the filter and oscillator configurations, respectively.

Electronically tunable mixed mode universal filter employing grounded capacitors utilizing highly versatile VD-DVCC

PurposeThis paper aims to achieve two main objectives. First, to introduce to the literature a new versatile active building block, namely, voltage differencing differential voltage current conveyor (VD-DVCC) for analog signal processing applications. Second, to design a novel electronically tunable mixed-mode universal filter. The designed filter provides low-pass, high-pass, band-pass, band-reject and all-pass responses in voltage-mode (VM), current-mode (CM), trans-impedance-mode (TIM) and trans-admittance-mode (TAM).Design/methodology/approachThe proposed filter uses two VD-DVCCs, three resistors and two capacitors. All the capacitors used are grounded, which is advantageous from the monolithic integration point of view. The VD-DVCC is designed and validated in Cadence software using CMOS 0.18 µm process design kit from Silterra Malaysia at a supply voltage of ±1 V.FindingsThe proposed novel filter enjoys many attractive features including as follows: the ability to operate in all four modes, no requirement of capacitive matching, tunability of quality factor (Q) independent of pole frequency, availability of both inverting and non-inverting outputs for VM and TIM mode, high output impedance explicit current output for CM and TAM, no requirement for double/negative input signals (voltage/current) for response realization and low active and passive sensitivities. The filter is designed for a pole frequency of 5.305 MHz. The obtained results bear a close resemblance with the theoretical findings.Originality/valueThe proposed novel filter structure requires a minimum number of active and passive components and provides operation in all four operating modes. The filter will find application in structures of mixed-mode systems.

Electronically Tunable Mixed-Mode Universal Filter Employing a Single Active Block and a Minimum Number of Passive Components

A recently developed active building block, namely Voltage Differencing Extra X Current Conveyor (VD-EXCCII), is employed in the design of multi input single output (MISO), electronically tunable mixed-mode universal filter. The filter provides low pass (LP), high pass (HP), band pass (BP), band reject (BR) and all pass (AP) responses in current-mode (CM), voltage-mode (VM), trans-impedance-mode (TIM) and trans-admittance-mode (TAM). The filter employs a single VD-EXCCII, three resistors and two capacitors. Additionally, a CM single input multi output (SIMO) filter can be derived from the same circuit topology by only adding current output terminals. The attractive features of the filter include: (i) the ability to operate in all four modes, (ii) the tunability of the Q factor independent of pole frequency, (iii) the low output impedance for the VM filter, (iv) the high output impedance current output for CM and TAM filters and (v) no requirement for double/negative input signals (voltage/current) for response realization. The VD-EXCCII and its layout is designed and validated in Cadence Virtuoso using 0.18 µm pdk from Silterra Malaysia with a supply voltage of ±1.25 V. The operation of the filter is examined at the 8.0844 MHz characteristic frequency. A non-ideal parasitic and sensitivity analysis is also carried out to study the effect of process and components spread on the filter performance.

Novel Electronically Tunable Biquadratic Mixed- Mode Universal Filter Capable of Operating in MISO and SIMO Configurations

In this paper, a novel electronically tunable biquadratic universal mixed-mode filter is presented. The filter is based on extra X current conveyor transconductance amplifier (EXCCTA), recently introduced by authors. The proposed filter employs two EXCCTAs, two capacitors, a switch, and four resistors. The filter can work in both multi-input-single-output (MISO) and single-input-multi-output (SIMO) configurations without change in its structure. The filter provides low-pass (LP), high-pass (HP), band-pass (BP), band-reject (BR) and all-pass (AP) responses in voltage-mode (VM), current-mode (CM), transimpedance-mode (TIM), and transadmittance-mode (TAM). The attractive features of the filter include (i) ability to operate in both MISO and SIMO configurations in all four modes, (ii) no requirement of capacitive matching, (iii) high output impedance in SIMO (CM & TAM) configuration, (iv) tunability of quality factor ( Q ) independent of natural frequency ( ) in MISO & SIMO configurations, (v) use of grounded capacitors in SIMO configuration, (vi) low output impedance for MISO (VM & TIM), (vii) high output impedance explicit current output for MISO (CM & TAM), and (viii) no requirement for double/negative input signals (voltage/current) in MISO configuration. The non-ideal gain and sensitivity analysis is also carried out to study the effects of process variations and passive components spread on filter performance. The filter is designed in Cadence Virtuoso using Silterra Malaysia 0.18µm PDK. The complete layout of the EXCCTA is designed and the parasitic extraction is done. The filter is tested at a supply voltage of ±1.25 V and the obtained results validate the theoretical findings.

High-Performance Electronically Tunable Analog Filter Using a Single EX-CCCII

In this paper, an electronically tunable mixed-mode analog filter is proposed, which employs only a single active element, namely Extra X Current Controlled Conveyor (EX-CCCII), two capacitors and a single resistor. The proposed circuit uses minimum components, so it is easy to integrate on chip. The circuit provides all four mode operations, namely current mode, voltage mode, transadmittance mode (TAM) and transimpedance mode without changing the circuit configuration. The circuit can provide all the five filter functions: low pass, high pass, band pass, band reject, and all pass by selecting appropriate input signals except the TAM. The parameters of the proposed circuit, i.e. angular frequency (ωo) and the quality factor (Q) are independent, while ωo is electronically tunable. The frequency range is 2.29 MHz to 22.9 MHz with a bias current variation from 1 to 100 µA. The effects of non-idealities and parasitics of the active element on the circuit performances are discussed. The results are verified through PSPICE simulation using a 0.18 µm CMOS technology with the supply voltages of ± 0.5 V. The power consumption is 13.5 µW at 1 µA, and 1.35 mW at 100 µA. The experimental setup further validates the theory and simulation results.

A Novel Differential Voltage Current Conveyor (DVCC) Based Instrumentation Amplifier

This research paper brings an instrumentation amplifier (IA) that exhibits all possible mode specifically voltage, current, transadmittance, and transimpedance mode using a single differential voltage current conveyor (DVCC) and few active resistors using transistors. The proposed design offers high range of 3 dB frequency for both differential gain (Ad ) and common mode rejection ratio (CMRR). The introduced topology of different IA are analyzed and simulated with PSPICE using 0.18 µm CMOS technology parameter for the realization of DVCC. Also, the experimental verification using commercially available Current Feedback Operational Amplifier (CFOA) named as IC AD844 is used to check the practical feasibility of proposed design. Apart from the ideal analysis of IA, nonidealities of the proposed work, temperature-dependent variation that affects the nature of IA, Monte Carlo simulations are well depicted in this report.