Programmable Microphone Circuit for Adaptive Noise Reduction
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Solution Overview
Problem
Existing microphones face challenges in achieving high performance across various acoustic situations due to inadequate signal conditioning, leading to issues like noise introduction, sensitivity variations, and overloading, particularly in small-sized devices with limited electrical charge storage and high input resistance requirements.
Innovation Solution
A semiconductor die with an integrated electronic circuit that includes a second circuit interconnected with the first circuit at nodes separate from the input node, allowing for precise signal transfer and noise reduction by controlling signal conditioning through a control input, enabling adaptive performance in different acoustic situations without loading the input node.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed signal conditioning circuit is used in the microphone capsule, then the circuit design is simple and cost-effective, but the microphone cannot adapt to different acoustic situations leading to performance degradation
Solution Approach 1:
The patent implements dynamic adaptability by enabling the microphone circuit to switch between different operating modes (high-pass filter mode and bypass mode) based on acoustic conditions. The mode selector circuit dynamically reconfigures the signal path to optimize performance for different acoustic situations, transforming a static fixed circuit into a dynamic adaptive system.
2Reliability
If the second circuit is interconnected at the input node, then signal transfer is direct, but the input node becomes overloaded and noise increases
Solution Approach 1:
The patent segments the circuit interconnection by providing separate input nodes for the first circuit and second circuit. This segmentation prevents overloading of a single input node while maintaining direct signal transfer paths. The mode selector circuit further segments the signal flow by routing signals through different paths depending on the selected mode, isolating noise and overloading effects.
3Reliability
If a more robust signal conditioning circuit is provided, then performance in various situations improves, but power consumption increases
Solution Approach 1:
The patent implements dynamic power management by enabling the microphone circuit to switch between different operating modes based on acoustic conditions. In high-pass filter mode, the circuit provides enhanced performance for noisy environments, while in bypass mode, it operates with lower power consumption for quieter situations. The mode selector circuit dynamically optimizes the balance between performance and power consumption.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration provides improved signal transfer precision and noise reduction, enhancing microphone sensitivity and reducing the risk of overloading, thereby achieving better performance in diverse acoustic conditions while maintaining low power consumption.
Implementation Method 1
The semiconductor die is configured so as to be mounted in a housing with a capacitive transducer. The first circuit is configured to receive an input signal from the transducer
Implementation Method 2
One of the members of the microphone, preferably the membrane, is charged by a constant electrical charge. The charge is either provided as an electrostatic charge captured on one of the members or provided by a voltage source e.g. a charge pump or voltage step-up circuit on the semiconductor die.
Data Source
AI summary
A semiconductor die with an integrated electronic circuit, configured so as to be mounted in a housing with a capacitive transducer e.g. a microphone. A first circuit is configured to receive an input signal from the transducer at an input node and to provide an output signal at a pad of the semiconductor die. The integrated electronic circuit comprises an active switch device with a control input, coupled to a pad of the semiconductor die, to operatively engage or disengage a second circuit interconnected with the first circuit so as to operate the integrated electronic circuit in a mode selected by the control input. That is, a programmable or controllable transducer. The second circuit is interconnected with the first circuit so as to be separate from the input node. Thereby less noise is induced, a more precise control of the circuit is obtainable and more advanced control options are possible.