Bridge Power Amplifier Current Sharing for Lower Heat in Vehicle Audio
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Solution Overview
Problem
Class AB power amplifiers face efficiency limitations, leading to overheating and potential chip degradation due to high power consumption, with existing solutions like class H and class D amplifiers either being costly or causing electromagnetic interference.
Innovation Solution
A power amplifier design incorporating two bridge-type amplifying circuits with a gating circuit that shares load current between them based on input signal thresholds, improving efficiency and reducing power consumption by switching between high-efficiency and standard modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If class AB power amplifier is used, then sound quality is good, but power consumption is high causing overheating and chip degradation
Solution Approach 1:
The patent implements dynamic switching between class AB and class D operating modes based on input signal characteristics. The control circuit dynamically adjusts the amplifying circuit's operation mode: using class AB for small signals and class D for large signals, thereby optimizing power consumption while maintaining sound quality and preventing overheating
Solution Approach 2:
The patent changes the operating parameters of the amplifying circuit by switching between different classes (AB and D) based on signal amplitude thresholds. This parameter change allows the system to adapt power consumption levels to actual usage conditions, reducing overall energy use while maintaining reliability
2Use of energy by moving object
If class H power amplifier is used, then power consumption is reduced, but cost increases due to power supply adjustment requirements
Solution Approach 1:
The patent merges the power amplification and power management functions into a single integrated circuit. The control circuit is built-in and automatically manages the switching between class AB and class D modes without requiring external power supply adjustment, thereby reducing both power consumption and device complexity compared to class H amplifiers
3Use of energy by moving object
If class D power amplifier is used, then power consumption is reduced, but electromagnetic interference and audio frequency interference occur
Solution Approach 1:
The patent dynamically switches between class AB and class D modes based on signal characteristics. For small signals where class D might cause interference, the system uses class AB mode. For large signals where efficiency is critical, it uses class D mode. This dynamic adaptation reduces electromagnetic interference while maintaining power efficiency
Solution Approach 2:
The control circuit acts as an intermediary that manages the switching between amplification modes. It monitors input signal characteristics and automatically selects the appropriate mode, mediating between the conflicting requirements of low power consumption and low electromagnetic interference
4Use of energy by moving object
If class D power amplifier is used, then power consumption is reduced, but additional inductance components are required increasing cost
Solution Approach 1:
The patent merges multiple amplification modes (class AB and class D) into a single integrated circuit, eliminating the need for separate external inductance components. The integrated design achieves power efficiency without requiring additional discrete components, thereby reducing device complexity and cost
Data Source
AI summary
A power amplifier includes: at least two first bridge type amplifying circuits and at least two second bridge type amplifying circuits; the negative pole of the first load of each first bridge type amplifying circuit is respectively coupled to the positive stage of the second load of each second bridge type amplifying circuits through a gating circuit. When both a first input signal input into one of the at least two first bridge type amplifying circuits and a second input signal input into one of the at least two second bridge type amplifying circuits are less than a preset threshold, the gating circuit is turned on, so that the one of the at least two first bridge type amplifying circuits and the one of the at least two second bridge type amplifying circuits can share load current by the gating circuit.