scholarly journals CMOS Current Feedback Operational Amplifier-Based Relaxation Generator for Capacity to Voltage Sensor Interface

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4488 ◽  
Author(s):  
Ladislav Polak ◽  
Roman Sotner ◽  
Jiri Petrzela ◽  
Jan Jerabek

This paper presents a simple relaxation generator, suitable for a sensor interface, operating as a transducer of capacitance to frequency/period. The proposed circuit employs a current feedback operational amplifier, fabricated in I3T25 0.35 μ m ON Semiconductor CMOS process, and four passive elements including a grounded capacitor (the sensed parameter). It offers a low-impedance voltage output of the generated square wave. Additional frequency to DC voltage converter offers output information in the form of voltage. The experimental capacitance variation from 6.8 nF to 100 nF yields voltage change in the range from 21 mV to 106 mV with error below 5% and sensitivity 0.912 mV/nF evaluated over the full range of change. These values are in good agreement with simulation results obtained from the Mathcad model of frequency to DC voltage transducer passive circuit.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Costas Laoudias ◽  
Costas Psychalinos

Differential Voltage Current Controlled Current Feedback Operational Amplifier is an attractive active element for realizing resistorless filters with a minimum active component count. This is verified through a design example, where a 3rd-order leapfrog filter has been realized using the AMS 0.35 μm CMOS process design kit. The performance of the Differential Voltage Current Controlled Current Feedback Operational Amplifier filter is evaluated and compared with that obtained by the corresponding filter, where Differential Voltage Current Controlled Current Conveyors have been employed.


ETRI Journal ◽  
2007 ◽  
Vol 29 (2) ◽  
pp. 212-218 ◽  
Author(s):  
Soliman A. Mahmoud ◽  
Ahmed H. Madian ◽  
Ahmed M. Soliman

Author(s):  
Muhammad Taher Abuelma’atti ◽  
Abdullah Yousef Alnafisa

<span>This paper presents a simple chaotic-masking system. The system uses a chaos generator built around a grounded memristor. The memristor is emulated using the current-feedback operational amplifier (CFOA). At the sending end the signal is masked by adding chaos. At the receiving end the signal is recovered by subtracting the chaos. The performance of proposed system is investigated using sinusoidal and square wave signals.</span>


2020 ◽  
Vol 29 (15) ◽  
pp. 2050247 ◽  
Author(s):  
Hasan Sozen ◽  
Ugur Cam

Meminductor is a nonlinear two-terminal element with storage energy and memory ability. To date, meminductor element is not available commercially as memristor and memcapacitor are. Therefore, it is of great significance to implement a meminductor emulator for breadboard experiment. In this paper, a flux-controlled floating/grounded meminductor emulator without a memristor is presented. It is built with commercially available off-the-shelf electronic devices. It consists of single operational transconductance amplifier (OTA), single multiplier, two second-generation current conveyors (CCIIs), single current-feedback operational amplifier (CFOA) and single operational amplifier. Using OTA device introduces an additional control parameter besides frequency and amplitude values of applied voltage to control the area of pinched hysteresis loop of meminductor. Mathematical model of proposed emulator circuit is given to describe the behavior of meminductor circuit. The breadboard experiment is performed using CA3080, AD844, AD633J and LM741 for OTA, CCII–CFOA, multiplier and operational amplifier, respectively. Simulation and experimental test results are given to verify the theoretical analyses. Frequency-dependent pinched hysteresis loop is maintained up to 5 kHz. The presented meminductor emulator tends to work as ordinary inductor for higher frequencies.


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