Design of chaotic analog noise generators with logistic map and MOS QT circuits

Abstract

In this paper a method to design chaotic analog noise generators using MOS transistors is presented. Two aspects are considered, the determination of operation regime of the MOS circuit and the statistical distribution of its output signal. The operation regime is related with the transconductance linear (TL: translinear) principle. For MOS transistors this principle was originally formulated in weak inversion regime; but, strong inversion regimen is used because in 1991, Seevinck and Wiegerink made the generalization for this principle. The statistical distribution of the output signal on the circuit, which should be a uniform distribution, is related with the parameter value that rules the transfer function of the circuit, the initial condition (seed) in the circuit and its operation as chaotic generator. To show these concepts, the MOS Quadratic Translinear circuit proposed by Wiegerink in 1993 was selected and it is related with the logistic map and its properties. This circuit will operate as noise generator if it works in strong inversion regime using current-mode approach when the parameter that rules the transfer function is higher than the onset chaos value (3.5699456…) for the logistic map.