Title
A Power-Efficient Capacitive Read-Out Circuit With Parasitic-Cancellation for MEMS Cochlea Sensors.
Abstract
This paper proposes a solution for signal read-out in the MEMS cochlea sensors that have very small sensing capacitance and do not have differential sensing structures. The key challenge in such sensors is the significant signal degradation caused by the parasitic capacitance at the MEMS-CMOS interface. Therefore, a novel capacitive read-out circuit with parasitic-cancellation mechanism is developed; the equivalent input capacitance of the circuit is negative and can be adjusted to cancel the parasitic capacitance. Chip results prove that the use of parasitic-cancellation is able to increase the sensor sensitivity by 35 dB without consuming any extra power. In general, the circuit follows a low-degradation low-amplification approach which is more power-efficient than the traditional high-degradation high-amplification approach; it employs parasitic-cancellation to reduce the signal degradation and therefore a lower gain is required in the amplification stage. Besides, the chopper-stabilization technique is employed to effectively reduce the low-frequency circuit noise and DC offsets. As a result of these design considerations, the prototype chip demonstrates the capability of converting a 7.5 fF capacitance change of a 1-Volt-biased 0.5 pF capacitive sensor pair into a 0.745 V signal-conditioned output at the cost of only 165.2 μW power consumption.
Year
DOI
Venue
2016
10.1109/TBCAS.2015.2403251
IEEE Trans. Biomed. Circuits and Systems
Keywords
DocType
Volume
chopper-stabilization,low capacitance measurement,sensor interface,capacitive read-out,parasitic-cancellation,mems cochlea
Journal
PP
Issue
ISSN
Citations 
99
1940-9990
5
PageRank 
References 
Authors
0.54
12
8
Name
Order
Citations
PageRank
Shiwei Wang1365.05
Thomas Jacob Koickal2446.55
Alister Hamilton311719.02
E. Mastropaolo492.02
Rebecca Cheung5142.61
Andrew Abel610511.72
Leslie S. Smith736340.34
Lei Wang814137.05