An analog trimming circuit based on a floating-gate device

The application of floating-gate elements as adjustable components in analog CMOS circuits such as amplifiers is proposed. A simple trimming circuit based on this principle and delivering a differential current is described. Experimental results of a differential difference amplifier (DDA) containing two such circuits are given. After trimming, an offset voltage of 10 mu V and a nonlinearity of 0.1% are achieved. Other analog circuits based on floating-gate elements like adjustable voltage sources and transconductances have been realized. Because they can be electrically reprogrammed, a wide range of applications, for example in neural nets, are possible. >