Publication detail

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

POLÁK, L. ŠOTNER, R. PETRŽELA, J. JEŘÁBEK, J.

Original Title

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

Type

journal article in Web of Science

Language

English

Original Abstract

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.

Keywords

capacity sensor interface; capacity measurement; current feedback operational amplifier; relaxation generator; square wave generator

Authors

POLÁK, L.; ŠOTNER, R.; PETRŽELA, J.; JEŘÁBEK, J.

Released

18. 12. 2018

Publisher

MDPI

Location

Basel (Switzerland)

ISBN

1424-8220

Periodical

SENSORS

Year of study

18

Number

12

State

Swiss Confederation

Pages from

1

Pages to

15

Pages count

15

URL

https://www.mdpi.com/1424-8220/18/12/4488

Full text in the Digital Library

http://hdl.handle.net/11012/179678

BibTex

@article{BUT151967,
  author="Ladislav {Polák} and Roman {Šotner} and Jiří {Petržela} and Jan {Jeřábek}",
  title="CMOS Current Feedback Operational Amplifier-Based Relaxation Generator for Capacity to Voltage Sensor Interface",
  journal="SENSORS",
  year="2018",
  volume="18",
  number="12",
  pages="1--15",
  doi="10.3390/s18124488",
  issn="1424-8220",
  url="https://www.mdpi.com/1424-8220/18/12/4488"
}