Field-Programmable Analog Arrays: A Floating-Gate Approach

Abstract

Field-programmable analog arrays (FPAAs) provide a method for rapidly prototyping analog systems. Currently available commercial and academic FPAAs are typically based on operational amplifiers (or other similar analog primitives) with only a few computational elements per chip. While their specific architectures vary, their small sizes and often restrictive interconnect designs leave current FPAAs limited in functionality, flexibility, and usefulness. Recent advances in the area of floating-gate transistors have led to an analog technology that is very small, accurately programmable, and extremely low in power consumption. By leveraging the advantages of floating-gate devices, a large-scale FPAA is designed that dramatically advances the current state of the art in terms of size, functionality, and flexibility. A large-scale FPAA is used as part of a mixed-signal prototyping platform to demonstrate the viability and benefits of cooperative analog/digital signal processing. This work serves as a roadmap for future FPAA research. While current FPAAs can be compared with the small, relatively limited, digital, programmable logic devices (PLDs) of the 1970s and 1980s, the floating-gate FPAAs introduced here are the first step in enabling FPAAs to support large-scale, full-system prototyping of analog designs similar to modern FPGAs.