A 6 µW per Channel Analog Biomimetic Cochlear Implant Processor Filterbank Architecture With Across Channels AGC
Venue
IEEE Transactions on Biomedical Circuits and Systems, vol. 9 (2015), pp. 72-86
Publication Year
2015
Authors
Guang Wang, Richard F. Lyon, Emmanuel M. Drakakis
BibTeX
Abstract
A new analog cochlear implant processor filterbank architecture of increased
biofidelity, enhanced across-channel contrast and very low power consumption has
been designed and prototyped. Each channel implements a biomimetic, asymmetric
bandpass-like One-Zero-Gammatone-Filter (OZGF) transfer function, using class-AB
log-domain techniques. Each channel's quality factor and suppression are controlled
by means of a new low power Automatic Gain Control (AGC) scheme which is coupled
across the neighboring channels and emulates lateral inhibition (LI) phenomena in
the auditory system. Detailed measurements from a five-channel silicon IC prototype
fabricated in a 0.35 µm AMS technology confirm the operation of the coupled AGC
scheme and its ability to enhance contrast among channel outputs. The prototype is
characterized by an input dynamic range of 92 dB while consuming only 28 µW of
power in total ~6 µW per channel) under a 1.8 V power supply. The architecture is
well-suited for fully-implantable cochlear implants.
