Analog signal processing for low-power sensor systems

Abstract

We present the potential of using Programmable Analog Signal processing techniques for impacting low-power portable applications like imaging, audio processing, and speech recognition. The range of analog signal processing functions available results in many potential opportunities to incorporate these analog signal processing systems with digital signal processing systems for improved overall system performance. We describes our programmable analog technology based around floating-gate transistors that allow for non-volitile storage as well as computation through the same device. We describe the basic concepts for floating-gate devices, capacitor-based circuits, and the basic charge modification mechanisms that makes this analog technology programmable. We describes the techniques to extend these techniques to program an array of floating-gate devices. We show experimental evidence for the factor of 1000 to 10,000 power efficiency improvement for programmable analog signal processing compared to custom digital implementations in Vector Matrix Multipliers (VMM), CMOS imagers with computation on the pixel plane with high fill factors, and Large-Scale Field Programmable Analog Arrays (FPAA), among others.