C1.4 - Identification and Automatic Compensation of Variable- Parallel-Conductance Effect in Capacitive Sensors
- Event
- AMA Conferences 2013
2013-05-14 - 2013-05-16
Nürnberg - Band
- Proceedings SENSOR 2013
- Chapter
- C1 - Sensor Electronics I
- Author(s)
- N. Mahdavi - Liebherr-Elektronik GmbH, Lindau (Germany)
- Pages
- 352 - 356
- DOI
- 10.5162/sensor2013/C1.4
- ISBN
- 978-3-9813484-3-9
- Price
- free
Abstract
Among some disadvantages, capacitive sensors are attributed with low manufacturing costs, the simple construction and flexible form as well as low power consumption. By issue of advanced silicon technology interfacing circuits for capacitive sensors is no more a difficulty.
Switched capacitor technique combined with sigma-delta modulators is very attractive Signal processing method for capacitive sensors. However this interfacing technique needs high speed and precise switches, with low charge injection and ultra-short break-before-make time. The latter requirement finds great importance, when the capacitive sensor has a considerable conductance. The situation will be more dramatic if the parallel conductance doesn’t remain constant and depending on environmental conditions varies during the measurement. This paper introduces a method, which identifies and compensates the variable-parallel-conductance effect in capacitive sensors automatically.