The analysis of the quantization noise in delta-sigma modulators is not a trivial task. State-of-the-art analysis methods include modelling the quantization noise as a uniform distributed white noise. However, it is not uncommon to observe limit cycle oscillations and tones at the output of a delta-sigma modulator. In most of the applications, these limit cycles and tones are strictly objectionable. Such an application, for instance, is a Fractional-N PLL frequency synthesizer, where idle tones and limit cycles generated from the delta-sigma modulator directly appear in the synthesized RF...