Spectrum Modulation for Switching Circuit Noise Mitigation
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Solution Overview
Problem
Switching circuits, such as DC-DC converters, generate noise spurs that interfere with other electrical devices due to their regular switching activity, and existing methods to mitigate this noise are complex and costly.
Innovation Solution
A circuit and method that utilize a signal generator with a modulation waveform generator to vary the switching frequency of a switching circuit over a range of frequencies, employing a ramp signal with adjustable amplitude and frequency to spread noise energy across a broader spectrum, thereby reducing noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If complex and expensive counting circuits are employed to vary the switching frequency, then noise spurs are mitigated, but device complexity and cost increase
Solution Approach 1:
The patent changes the frequency parameter of the switching circuit by modulating it with a spread spectrum signal. The modulation waveform generator creates frequency variations that spread the noise energy across a broader spectrum, reducing peak noise spurs without requiring complex counting circuits. This is achieved by modifying the switching frequency parameter dynamically through signal modulation.
Solution Approach 2:
The patent introduces a modulation waveform generator as an intermediary component that produces the spread spectrum modulation signal. This intermediary generates the frequency-modulating signal that is then applied to the switching circuit, avoiding the need for complex counting circuits while still achieving noise spur mitigation through frequency variation.
2Object-affected harmful factors
If switching frequency is varied to spread noise energy, then noise interference is reduced, but device complexity increases
Solution Approach 1:
The modulation waveform generator serves as an intermediary that simplifies the frequency variation process. Instead of using complex counting circuits to vary the switching frequency, this intermediary component generates the appropriate modulation signal that achieves the same noise spreading effect with simpler circuitry.
Solution Approach 2:
The patent replaces the mechanical/electronic counting circuit approach with a signal processing approach using modulation waveform generation. This substitution uses signal modulation techniques rather than complex digital counting logic, reducing device complexity while maintaining the noise spreading functionality.
Data Source
AI summary
A circuit includes a signal generator to generate an output signal to vary the switching frequency of a switching circuit to mitigate noise in the switching circuit. The signal generator includes a modulation waveform generator (MWG) to generate a ramp signal in response to a numerical input and a switching signal from the switching circuit. The ramp signal is employed to modulate the frequency of the output signal of the signal generator over a range of frequencies from a minimum frequency to a maximum frequency. A frequency adjuster circuit modulates the amplitude of the ramp signal by adjusting at least one of the minimum frequency or the maximum frequency of the range of frequencies.