IMST (Booth 2224) has developed a fractional-N PLL spur simulator, which will be highlighted at IMS 2011.

SpurSIM can calculate fractional, coupling and reference spurs for all PLL types. Both, single and dual loop PLLs can be simulated. In addition, SpurSIM allows the calculation of phase noise, also in combination with spurs.

Various Sigma-Delta structures can be used, such as a series construction or a MASH. Calculation is done based on transistor level based charge pump linearity curves, which can be read from external simulation software. Moreover, spur elimination techniques can be applied. The simulator features a charge pump construction set allowing the generation of analytical charge pump curves. These curves can serve as specification for any transistor level design.