Adaptive Residue PLL Control for Predictable Phase Jitter
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Solution Overview
Problem
Phase locked loops with digitally-controlled oscillators face challenges in generating output signals with predictable phase jitters due to incorrect phase information from residue values, leading to unpredictable phase jitters in output signals.
Innovation Solution
The implementation of a phase locked loop that includes a phase detector, digital filter, and logic IC, which generates an adaptive residue by modifying initial residue signals based on parameters from the phase detector and oscillator, ensuring the digitally-controlled oscillator produces output signals with phase jitters lower than a predetermined value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the phase detector compares reference value with DCO output signal to generate residue value, then the phase detection function is achieved, but the phase information becomes incorrect leading to unpredictable phase jitters
Solution Approach 1:
The patent introduces an intermediary calculation process that uses the known reference value and the measured phase difference to compute an expected residue value. This expected value serves as a mediator to correct the actual residue value, ensuring both accurate phase detection and predictable phase jitter behavior. The intermediary calculation bridges the gap between measurement and reliability.
Solution Approach 2:
The patent implements feedback by comparing the actual residue value with the expected residue value calculated from reference information. The system uses this feedback to adjust and correct the residue value, ensuring that phase jitters remain predictable while maintaining accurate phase detection functionality.
2Reliability
If extensive residue value scanning is performed to ensure predictable phase jitters, then phase jitter predictability improves, but system complexity and cost increase
Solution Approach 1:
The patent performs preliminary calculations of the expected residue value using known reference information before actual phase detection. By pre-computing what the residue value should be based on reference values and expected phase relationships, the system eliminates the need for extensive scanning and testing, reducing complexity while ensuring predictable phase jitters.
Solution Approach 2:
The system uses its own reference values and internal parameters to generate the expected residue value, making the system self-sufficient. This self-service approach eliminates the need for external calibration or extensive scanning procedures, reducing system complexity while maintaining reliability.
3Productivity
If the DCO generates output signals based on residue value, then oscillation function is achieved, but phase jitters become unpredictable exceeding predetermined threshold
Solution Approach 1:
The patent replaces the direct mechanical linkage between residue value and DCO control with a computational substitution. Instead of directly using the raw residue value, the system substitutes it with a corrected value derived from reference information and expected phase relationships. This substitution ensures that the DCO generates signals with controlled phase jitters while maintaining productivity.
Data Source
AI summary
A circuit includes a phase locked loop and a logic IC. The phase locked loop is coupled to the logic IC. The logic IC is configured for generating an adaptive residue according to a first parameter and a second parameter. The phase locked loop is configured for providing the first parameter and the second parameter, and the phase locked loop generates an oscillator signal based on the adaptive residue.