PWM Modulator Synchronization Circuit for Pulse-Center Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional synchronization circuits for self-oscillating PWM modulators face challenges in achieving precise synchronization, leading to spectral noise components around the switching frequency, which require complex high-order filters, increasing circuit complexity and limiting the ability to reject spectral components effectively.
Innovation Solution
The synchronization circuit adjusts the self-oscillation frequencies of PWM modulators to be identical by introducing a control input to set the oscillation frequency, using a phase detector to ascertain phase differences, and integrating these differences to generate synchronization control signals that actuate delay circuits, ensuring the signal pulse centers are in sync, thereby eliminating frequency components at the switching frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional synchronization circuits are used for self-oscillating PWM modulators, then the modulators can operate independently, but spectral noise components appear around the switching frequency requiring complex high-order filters
Solution Approach 1:
The patent implements a feedback mechanism where the output of one PWM modulator is fed back to control the timing of the other modulator through a phase detector and delay circuit. This feedback loop continuously adjusts the timing of the second modulator to maintain synchronization with the first modulator, thereby eliminating spectral noise components and allowing the use of simpler filters.
Solution Approach 2:
The patent introduces an intermediary synchronization circuit comprising a phase detector and delay circuit that mediates between the two PWM modulators. The phase detector compares the timing of signals from both modulators and generates a control signal that adjusts the timing of the second modulator, serving as an intermediary that enables precise synchronization without requiring complex filtering.
2Device complexity
If the two PWM modulators are not in sync, then circuit operation is simple, but spectral noise components require high-order OOB filters increasing circuit complexity
Solution Approach 1:
The synchronization circuit uses feedback from the phase detector to continuously monitor and adjust the timing of the second PWM modulator. This feedback mechanism detects phase differences and applies corrective timing adjustments, thereby eliminating spectral noise components at the switching frequency while maintaining relatively simple circuit architecture.
Solution Approach 2:
The patent applies preliminary timing adjustment to the second PWM modulator by introducing a variable delay circuit that pre-adjusts the timing of the second modulator based on phase detection. This preliminary action prevents the generation of spectral noise components before they can affect the output, rather than requiring complex filtering afterward.
3Reliability
If output-side coupling is made indirectly as in prior art, then circuit isolation is maintained, but synchronization precision is insufficient to reject spectral components
Solution Approach 1:
The patent introduces a phase detector as an intermediary that provides strong coupling between the two PWM modulators. The phase detector directly compares the timing signals from both modulators and generates precise timing adjustment signals, achieving strong synchronization precision while maintaining circuit isolation through the use of this intermediary control mechanism.
Data Source
AI summary
A synchronization circuit for synchronizing at least two self-oscillating PWM modulators, each outputting a respective pulse-width-modulated output signal comprising signal pulses with signal pulse centers, shifts the timings of the signal pulses relative to one another such that their signal pulse centers are in sync.