1. A method for determining selected parameters of a noise characterization equation which describes a noise performance of a device as a function of a controllable variable relevant to the device, comprising: selecting a number of different values of the controllable variable relevant to the device, the number of different values being equal to or larger than the number of parameters that are to be determined; measuring the noise performance of the device for the different values; utilizing the noise characterization equation to set up a number of independent relations which relate the parameters with the measurement results, the number of independent relations being equal to the number of parameters that are to be determined; and determining the parameters from the relations.