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Book Description
This book reports the development of an integrated low-power readout
circuit for a capacitive sensor with 40 - 60 pF basic capacitance. The
sensor is used to detect screw loosening in an osteosynthesis
measurement system. To ensure detection of screw loosening the readout
circuit must be able to measure capacitance changes of at least 0.25 pF.
Several readout techniques for capacitive sensors are investigated and
evaluated for this application. Finally two types are developed and
simulated, a Wien-bridge oscillator and a switched capacitor (SC)
capacitance to voltage (C/V) converter. The oscillator is simulated with
Cadence in a 0.35 µm triple-well, 4-metal, and double poly CMOS process
from austriamicrosystems. The Wien-bridge is adapted for CMOS
integration. Additionally, a SC C/V-converter is developed and simulated
in the same process to compare the readout techniques. The target
audience for this book are electronic engineers, students and people who
are interested in working and developing with simulation tools.
About the Author
After an apprenticeship to an electronic
technician, he achieved his vocational diploma by the constinuation
education. From 2002 to 2006 he studied telecommunication engineering at
the University of Applied Science in Offenburg (Germany). He is
currently acting in the research and development of driver circuits for
semiconductor lasers. |
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