Bidirectional Switching Converter Frequency Modulation for Audible Noise
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Solution Overview
Problem
Electronic devices with bidirectional switching converters often experience audible noise due to switching frequencies falling within the audible frequency range, which can be bothersome and inefficiently addressed by existing technologies.
Innovation Solution
The electronic device incorporates a switching modulation circuit that adjusts the switching frequency to be outside the audible range by generating a second frequency that is a multiple or fraction of the initial frequency, based on load current conditions, using transistors, inductors, and control signals managed by a controller and latch circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the switching frequency is set within the audible frequency range for efficient power management, then power conversion efficiency is improved, but audible noise is generated causing user discomfort
Solution Approach 1:
The patent changes the switching frequency parameter dynamically based on load conditions. When the load current exceeds a threshold, the switching frequency is adjusted from a first frequency (within audible range) to a second frequency (outside audible range), eliminating audible noise while maintaining efficient power conversion under heavy load conditions
Solution Approach 2:
The patent implements dynamic switching frequency adjustment based on real-time load current detection. The controller monitors load conditions and dynamically switches between different frequency modes, making the system adaptive to varying operational requirements and eliminating audible noise during high-power operation
2Object-affected harmful factors
If the switching frequency is increased to reduce audible noise, then audible noise is reduced, but power loss increases due to higher switching losses
Solution Approach 1:
The patent changes the switching frequency parameter dynamically based on load conditions. When the load current exceeds a threshold, the switching frequency is adjusted from a first frequency (within audible range) to a second frequency (outside audible range), eliminating audible noise while maintaining efficient power conversion under heavy load conditions
Solution Approach 2:
The patent implements dynamic switching frequency adjustment based on real-time load current detection. The controller monitors load conditions and dynamically switches between different frequency modes, making the system adaptive to varying operational requirements and eliminating audible noise during high-power operation
3Object-affected harmful factors
If the switching frequency is dynamically adjusted based on load current, then audible noise is reduced, but device complexity increases due to additional control circuits
Solution Approach 1:
The controller performs multiple functions: it monitors load current, determines when audible noise may occur, adjusts switching frequency accordingly, and manages power conversion. This multi-functionality reduces the need for separate dedicated circuits for each function, thereby limiting the increase in overall device complexity while still achieving audible noise reduction
Data Source
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AI summary
An electronic device is provided. The electronic device includes: a first transistor configured to connect an input voltage node to a switching node; a second transistor configured to connect the switching node to a ground node; a latch circuit configured to generate a first signal having a first frequency and to control the first frequency based on a level of a load current; a switching modulation circuit configured to generate a second signal having a second frequency which is 1/N (where N is a natural number) times the first frequency; and a controller configured to control each of the first transistor and the second transistor, based on the second signal.