Nonlinear dynamical systems utilizing pulse modulation signals and a CMOS chip generating arbitrary chaos

This paper presents nonlinear dynamical systems utilizing pulse modulation signals suitable for VLSI implementation. The proposed circuits implement discrete-time continuous-state dynamics by analog processing in time domain. Arbitrary nonlinear transfer functions can be generated using the conversion from an analog voltage to a pulse-width modulation (PWM) signal. The nonlinear waveforms that have the same shape as the inverse function of the desired transfer function are supplied. A CMOS chip generating arbitrary chaos has been designed and fabricated using a 0.4 /spl mu/m CMOS process. Chaos using the tent map and logistic map has successfully been observed using the chip.