Run-Time Programming of Analog Circuits Using Floating-Gate Transistors

The ability to recalibrate a system is an important feature in allowing that system to maintain optimal performance even in the face of new demands placed on that system by environmental changes or even consumers' desires. The use of floating-gate (FG) transistors provides programmability to analog circuitry and, hence, the ability to recalibrate an analog system. If the FG transistors are programmed indirectly by using a second transistor to perform hot-electron injection, then an analog system can be recalibrated and reprogrammed without ever having to take the circuit out of operation. In this paper, we present a technique for adjusting circuit properties while still in operation as well as example circuits in which this run-time programming is conducted.

I. Introduction

Designing electronics that are robust enough to withstand varying environmental conditions is a difficult task. As a result, recalibration circuitry is often employed to adjust the system until it performs within a desired tolerance. Additionally, electronics users often desire a change in performance, and creating a design that can account for user-desired settings can be an equally burdensome design challengs. In consequence, electronics with static properties are often less desirable than electronics that offer programmability because programmability translates into versatility.