Initial Condition-Dependent Spur Pattern Induced by Undithered MASH DDSM Divider Controller

The Multi-stAge noiSe sHaping digital delta-sigma modulator (MASH DDSM) is the most used divider controller architecture for fractional-N frequency synthesis. It is well-known that a MASH DDSM divider controller can cause input-dependent spurious tones in the output spectrum of a synthesizer. This paper discusses MASH 1-1-1 DDSM-induced spurious tone patterns that are dependent on the initial conditions.