Decimated Phase Detector Circuit for Jitter Filtering

The patent segments the charge pump operation into multiple discrete steps within each phase detector cycle. Instead of a single continuous charge transfer, the charge pump performs multiple smaller charge transfers (e.g., 4 steps per cycle), where each step transfers a fraction of the total charge. This segmentation reduces the impact of mismatch and charge injection non-idealities in any single step, as the errors average out over multiple steps while still achieving the required jitter filtering through the integrated effect.

The patent implements periodic action by dividing the charge pump operation into multiple periodic steps within each phase detector cycle. The charge pump operates in a rhythmic sequence of discrete charge transfer steps rather than continuous operation. This periodic multi-step approach allows the system to achieve higher effective bandwidth by distributing the charge transfer over time while maintaining reliable operation, as each periodic step uses small current levels that don't overwhelm charge injection effects.

The patent merges multiple phase detector output cycles into a single integrated control signal for the voltage-controlled oscillator. By accumulating phase error information from multiple BBPD cycles and integrating the decimated UP/DOWN signals, the system combines the information content of multiple measurements into one comprehensive control action. This merging approach maintains information fidelity despite reduced signal frequency, as the integrated result preserves the cumulative phase alignment information that would otherwise be lost through simple decimation.