An adaptive microphone preamplifier for low power applications

In this paper, we present a microphone preamplifier that adapts its power consumption according to the input signal's instantaneous bandwidth. The preamplifier's dynamic range and gain keep reasonably constant, regardless of the power consumption. The preamplifier was fabricated with a 0.5-μm CMOS process. The measurement results show it has over 79.5-dB dynamic range with 53.4% power saving compared to its non-adaptive counterpart.

[1]  Dingkun Du,et al.  A bio-inspired ultra-low-power spike encoding circuit for speech edge detection , 2011, 2011 IEEE Biomedical Circuits and Systems Conference (BioCAS).

[2]  Germano Nicollini,et al.  A 3.3-V 800-nV/sub rms/ noise, gain-programmable CMOS microphone preamplifier design using yield modeling technique , 1993 .

[3]  Dingkun Du,et al.  Efficient speech edge detection for mobile health applications , 2011, 2011 IEEE Biomedical Circuits and Systems Conference (BioCAS).

[4]  Fang Chen,et al.  Speech-based cognitive load monitoring system , 2008, 2008 IEEE International Conference on Acoustics, Speech and Signal Processing.

[5]  Max A. Little,et al.  Accurate Telemonitoring of Parkinson's Disease Progression by Noninvasive Speech Tests , 2009, IEEE Transactions on Biomedical Engineering.

[6]  W. Guggenbuhl,et al.  A versatile building block: the CMOS differential difference amplifier , 1987 .