Power Converter Noise Reduction via Periodic Switching Gating
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Solution Overview
Problem
Conventional power converters introduce substantial noise due to high-frequency switching, which affects the accuracy of feedback sensing and control in power supply monitoring, making it difficult to precisely measure output current delivered to a load.
Innovation Solution
A controller adjusts the operation of the power converter during a specific window of time to reduce noise, either by discontinuing switching, modifying switching frequency, or controlling the slew rate, allowing for more accurate sampling of the feedback signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the power converter operates at high switching frequency to maintain power delivery, then power conversion efficiency is improved, but noise coupling into feedback signals increases
Solution Approach 1:
The patent implements periodic action by temporarily suspending power converter switching operations during specific sampling windows. The controller periodically gates the switching signals to the power converter, creating noise-free intervals that coincide with feedback signal sampling periods, while maintaining normal high-frequency switching during non-sampling periods to preserve power conversion efficiency.
Solution Approach 2:
The patent applies preliminary action by proactively scheduling the suspension of switching operations before feedback sampling occurs. The controller anticipates the need for noise-free sampling windows and preemptively gates the switching signals during these predetermined intervals, ensuring that noise does not contaminate the feedback signals before sampling takes place.
2Measurement precision
If the power converter switching is discontinued during sampling windows to reduce noise, then measurement precision is improved, but power delivery to the load is interrupted
Solution Approach 1:
The patent uses periodic action by implementing brief, periodic suspensions of switching operations that coincide with feedback sampling windows. These temporary interruptions are scheduled periodically at intervals that allow the output capacitor to maintain voltage during the brief sampling periods, thus achieving measurement precision without significant power delivery interruption.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the duty cycle and timing of switching operations. The controller modifies switching parameters temporarily during sampling windows to reduce noise, while maintaining adequate power delivery through proper duty cycle management and output capacitor sizing that ensures continuous power supply despite brief switching suspensions.
3Object-affected harmful factors
If the switching frequency is modified during sampling to reduce noise, then noise interference is reduced, but power conversion efficiency decreases
Solution Approach 1:
The patent implements periodic action by maintaining high switching frequency during non-sampling periods to preserve power conversion efficiency, while temporarily reducing or suspending switching during brief sampling windows to eliminate noise interference. This periodic modulation of switching frequency achieves both goals: high efficiency during power delivery and low noise during sampling.
Solution Approach 2:
The patent applies dynamics by making the switching frequency adjustable and time-dependent. The controller dynamically changes the switching frequency based on whether the system is in a sampling window or normal operation mode, optimizing both power conversion efficiency and noise reduction at different times without compromising overall system performance.
Data Source
AI summary
An apparatus includes a controller. The controller receives feedback associated with a device powered by a power source. Sampling of the feedback associated with the device is susceptible to noise caused by a power converter in a vicinity of the controller. To achieve more accurate sampling of the feedback, the controller adjusts operation of the power converter during a window of time in which the power source powers the device. The adjusted operation reduces noise caused by the power converter such that, during the window of time in which the operation of the power converter is adjusted, the controller derives one or more accurate sample values from the received feedback.