Large-scale field-programmable analog arrays for analog signal processing

TLDR

Field‑programmable analog arrays enable rapid analog prototyping, yet existing devices are limited by few primitives and restrictive interconnects; recent floating‑gate transistor advances promise larger, digitally controllable analog circuitry that can be integrated with FPGAs. This paper introduces a new generation of large‑scale FPAAs that use floating‑gate transistors to provide area‑efficient, accurately programmable analog circuitry for seamless integration into digital/mixed‑signal systems. The authors fabricated the FPAA using floating‑gate transistors as the sole programmable element and performed characterization and system‑level experiments to evaluate its performance. Characterization and system‑level experiments demonstrate that the fabricated FPAA achieves the targeted area efficiency, programmability, and integration capability, markedly advancing the state of the art.

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 and flexibility. For FPAAs to enter the realm of large-scale reconfigurable devices such as modern field-programmable gate arrays (FPGAs), new technologies must be explored to provide area-efficient accurately programmable analog circuitry that can be easily integrated into a larger digital/mixed-signal system. Recent advances in the area of floating-gate transistors have led to a core technology that exhibits many of these qualities, and current research promises a digitally controllable analog technology that can be directly mated to commercial FPGAs. By leveraging these advances, a new generation of FPAAs is introduced in this paper that will dramatically advance the current state of the art in terms of size, functionality, and flexibility. FPAAs have been fabricated using floating-gate transistors as the sole programmable element, and the results of characterization and system-level experiments on the most recent FPAA are shown.