Spurious -Tone Suppression Techniques Applied to a Wide-Bandwidth 2.4GHz Fractional-N PLL

This paper describes a fractional-N PLL IC based on a new digital quantizer that replaces the DeltaSigma modulator (DeltaSigmaM) used in conventional designs. In combination with a charge pump offset technique and a sampled loop filter the new quantizer enables state-of-the-art fractional spur performance without sacrificing BW.