A Switched-Capacitor Digital Capacitance Bridge
Kenzo Watanabe,Gabor C. Temes +1 more
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TLDR
In this article, a switched-capacitor bridge is developed for capacitance measurements, which consists of four arms connected between the low-impedance output and virtual ground nodes of an op-amp and hence is insensitive to parasitic capacitances.Abstract:
A switched-capacitor bridge has been developed for capacitance measurements. It consists of four arms connected between the low-impedance output and virtual ground nodes of an op-amp, and hence is insensitive to parasitic capacitances. The capacitance to be measured is first given a proportional charge. This charge is then compared successively with charges quantized by means of a programmable binary-weighted capacitor array, until a balance is reached. This digital balance operation makes it possible to accomodate an automatic calibration scheme, which affords, in conjunction with the parasitic-insensitive configuration, an accurate measurement. Error analysis has shown that a 10-bit quantization accuracy and a relative error as small as 0.1 percent are attainable when the bridge is fabricated in LSI circuit form using present MOS technologies. A prototype bridge built using discrete components has confirmed the principles of operation. Examples of measurement are also given.read more
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References
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All-MOS charge-redistribution analog-to-digital conversion techniques. II
TL;DR: This second paper describes a two-capacitor successive approximation technique which, in contrast to the first, requires considerably less die area, is inherently monotonic in the presence of capacitor ratio errors, and which operates at somewhat lower conversion rate.
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MOS switched-capacitor filters
TL;DR: In this paper, the basic operation of switched-capacitor filters is reviewed, followed by a discussion of the properties of the various circuit building blocks in MOS technology, and a summary of several filter organizations which appear to be well suited to switch-capACitor implementation is presented.
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Matching properties, and voltage and temperature dependence of MOS capacitors
TL;DR: In this article, the matching properties of MOS capacitors are modeled and compared with measured data, and a weighted-capacitor array design approach is described, where the voltage and temperature dependence of capacitors were analyzed, modeled, and compared.
Journal ArticleDOI
Precision Capacitor Ratio Measurement Technique for Integrated Circuit Capacitor Arrays
TL;DR: A novel technique based on a special algorithm in which the capacitor array is used as a precision voltage divider is developed and a capacitor array tester consisting of both hardware and software has been built which executes this algorithm.
Journal ArticleDOI
A Universal Four-Pair Impedance Bridge
TL;DR: In this article, a 10 ppm four-terminal-pair audio-frequency impedance bridge is described, which can be operated either in an impedance mode, for self-inductance, mutual inductance, and resistanre measurements; or in an admittance mode for capacitance and conductance measurements.