Two schemes of switched-capacitor chaotic neuron circuits with bipolar/unipolar output function

The paper presents two schemes to realize chaotic neuron circuits with both bipolar and unipolar output functions. In the first method (Method 1), two output functions, i.e., bipolar and unipolar functions, are implemented by a simple nonlinear output function circuit consisting of a CMOS inverter, a CMOS resistor and an output stage. One of those two characteristics is externally selectable. Characteristics of the chaotic neuron circuit using method 1 are measured from a chip. The other method (Method 2) utilizes one bipolar output function circuit that is the same as in Method 1, while a specially arranged switched-capacitor (SC) input stage is used to obtain the unipolar characteristic. The circuit using Method 2 is simulated using HSPICE simulations