Subthreshold CMOS Array for Generating a Gaussian Distribution of Currents

This brief presents a subthreshold CMOS array whose spatial distribution of output currents approximates a Gaussian, and the distribution has an independently controllable mean and standard deviation. This Gaussian distribution naturally results from the transistor physics of subthreshold CMOS equations and the symmetry imposed in the network. The usefulness of the circuit array is demonstrated in a system-level example by using the currents to drive integrate-and-fire silicon neurons in which the neuronal input current and the resulting interspike interval are inversely related. The circuit and silicon neuron arrays were fabricated on the same integrated-circuit chip using the MOSIS AMI 0.5-mum process, and testing yielded experimental results that matched well with theoretical analysis