Limitations of a relaxation oscillator in capacitance measurements
TLDR
The results are compared with theoretical values derived in terms of the finite gain-bandwidth (GB) product and the slew rate of an op-amp and the response delay of a comparator to validate the theoretical derivation which gives the design criteria of a relaxation oscillator for capacitance measurements and sensor signal processing.Abstract:
Oscillation periods of a relaxation oscillator consisting of an op-amp-based integrator and a comparator are measured over a wide range of RC integration constants, and the results are compared with theoretical values derived in terms of the finite gain-bandwidth (GB) product and the slew rate of an op-amp and the response delay of a comparator The comparison validates the theoretical derivation which gives the design criteria of a relaxation oscillator for capacitance measurements and sensor signal processingread more
Citations
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References
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A novel low-cost capacitive-sensor interface
TL;DR: In this article, the authors describe the design of a new capacitive sensor interface based on the use of a novel type of oscillator whose frequency is insensitive to low and high-frequency interfering signals by the application of a third order high-pass filter and special dither techniques.
Journal ArticleDOI
A high-resolution, linear resistance-to-frequency converter
K. Mochizuki,Kenzo Watanabe +1 more
TL;DR: In this article, a resistance-to-frequency converter consisting of a Wheatstone bridge followed by an integrator and a comparator is described, whose frequency changes linearly with a resistance change detected by the bridge.
Journal ArticleDOI
Highly accurate resistance deviation to frequency converter with programmable sensitivity and resolution
C. D. Johnson,H. Al Richeh +1 more
TL;DR: In this paper, a circuit based on a DC bridge is presented which allows for highly accurate and linear conversion of resistance deviation to frequency, and a test of the converter demonstrates that sensitivities of 1 part in 105 are obtained using standard electronic components.
Proceedings ArticleDOI
A relaxation-oscillator-based interface for high-accuracy ratiometric signal processing of differential-capacitance transducers
TL;DR: For high-accuracy signal processing of differential-capacitance transducers, an interface circuitry is developed based on a relaxation oscillator that can detect the capacitance change as small as 0.01% of the total capacitance.