Nonlinear switched-current CMOS IC for random signal generation

A nonlinear switched-current circuit is presented that implements a chaotic algorithm for the generation of broadband, white analogue noise. The circuit has been fabricated in a double-metal, single-poly 1.6 mu m CMOS technology and uses a novel, highly accurate CMOS circuit strategy to realise piecewise-linear characteristics in the current-mode domain. Measurements from the silicon prototype show a flat spectrum from DC to approximately 30% of the clock frequency, for a clock frequency of 500kHz.