Title
CMOS Current Feedback Operational Amplifier-Based Relaxation Generator for Capacity to Voltage Sensor Interface.
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 13T25 0.35 mu 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.
Year
DOI
Venue
2018
10.3390/s18124488
SENSORS
Keywords
Field
DocType
capacity sensor interface,capacity measurement,current feedback operational amplifier,relaxation generator,square wave generator
Current-feedback operational amplifier,Electronic engineering,CMOS,Engineering,Voltage sensor
Journal
Volume
Issue
ISSN
18
12.0
1424-8220
Citations 
PageRank 
References 
0
0.34
0
Authors
4
Name
Order
Citations
PageRank
Ladislav Polak14611.44
Roman Sotner26525.81
Jiri Petrzela32311.58
Jan Jerabek46724.54