In the paper a new method, called the Noise Scattering Pattern (NSP) method, for RTS noise identification in a noise signal is presented. Examples of patterns of the NSP method are included.

The course of design of an optocoupler's PSpice macromodel including noise sources is described. The PSpice macromodel is proposed for the low frequency range. The PSpice model of a MOSFET transistor was applied as the noise source type 1/fα in an optocoupler PSpice macromodel. In the enhanced macromodel the value of an exponent α can be changed in the range of 0.8-1.25.