Analog floating-gate, on-chip auditory sensing system interfaces

This paper describes our current efforts toward creating cooperative analog-digital signal-processing systems for auditory sensor and signal-processing applications. We address resolution issues that affect the choice of signal-processing algorithms arriving from an analog sensor. We discuss current analog circuit approaches toward the front-end signal processing by reviewing major programmable analog building blocks and showing how they can be interconnected to create a complete system. We also discuss our current IC approaches using this technology for noise suppression, as well as our current analog signal-processing front-end system for speech recognition. Experimental data is presented from circuits fabricated using a 0.5 μm nwell CMOS process available through MOSIS.