DocumentCode :
3375949
Title :
An internally non-linear ADC for a ΣΔ accelerometer loop
Author :
Schmid, Hanspeter ; Sigel, Sven ; Pastre, Marc ; Kayal, Maher ; Zwahlen, Pascal ; Nguyen, Anne-Marie
Author_Institution :
Inst. of Microelectron., Univ. of Appl. Sci., Windisch, Switzerland
fYear :
2010
fDate :
May 30 2010-June 2 2010
Firstpage :
2155
Lastpage :
2158
Abstract :
If an analog-to-digital converter (ADC) is used within a ΣΔ converter such that the loop filter is mixed signal, then the ADC does not need to have the full resolution of the ΣΔ converter, and its input values will not be uniformly distributed over the input range. In this paper, we argue that the best input distribution to use as a general model is the maximum-entropy distribution (for location parameters: the Gaussian distribution). We then describe an externally linear ADC with non-linearly spaced decision boundaries implemented in 0.6μm CMOS and show measurement results of a 19-bit dynamic range ΣΔ accelerometer loop inside which the ADC reaches more than the required 7-bit performance with only 26 decision levels.
Keywords :
accelerometers; analogue-digital conversion; accelerometer loop; analog to digital converter; loop filter; maximum entropy distribution; nonlinear ADC; nonlinear spaced decision boundary; size 0.6 mum; Acceleration; Accelerometers; Analog-digital conversion; Dynamic range; Filters; Force feedback; Gaussian distribution; Mechanical sensors; Probability distribution; Sensor systems;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Circuits and Systems (ISCAS), Proceedings of 2010 IEEE International Symposium on
Conference_Location :
Paris
Print_ISBN :
978-1-4244-5308-5
Electronic_ISBN :
978-1-4244-5309-2
Type :
conf
DOI :
10.1109/ISCAS.2010.5537224
Filename :
5537224
Link To Document :
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