Digital Microphone Multipath AGC for Low-Power High Dynamic Range
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional digital microphones face challenges in achieving high dynamic range while maintaining low power consumption and compact size, especially in applications requiring wide signal range and low noise, such as mobile devices.
Innovation Solution
The implementation of a multipath digital microphone system that employs automatic gain control (AGC) and multipath digital signal processing chains, allowing for efficient switching between signal paths to optimize power and die area usage, while minimizing audible artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional high DR ADC or AGC techniques are employed to improve dynamic range, then dynamic range is improved, but power consumption and die area increase excessively
Solution Approach 1:
The patent divides the audio signal processing into multiple paths: a first path for low-level signals with higher gain and a second path for high-level signals with lower gain. This segmentation allows each path to be optimized for its specific signal range, achieving high dynamic range without requiring a single high-power component to handle the entire range.
Solution Approach 2:
The system dynamically switches between different signal paths based on the input signal level. The switching mechanism allows the microphone to adapt its gain characteristics in real-time, optimizing power consumption by activating only the necessary path for the current signal conditions rather than continuously powering all components.
2Measurement precision
If conventional high DR ADC or AGC techniques are employed to improve dynamic range, then dynamic range is improved, but die area increases excessively
Solution Approach 1:
The patent segments the signal processing into multiple paths with different gain characteristics. By processing low-level and high-level signals through separate optimized paths, the system achieves high dynamic range without requiring a single large-area high-precision ADC, thus reducing overall die area.
Solution Approach 2:
The system changes the gain parameter dynamically by switching between different signal paths. This allows the use of smaller, less precise ADCs in each path while achieving the equivalent performance of a single large-area high-precision ADC through parameter adaptation.
3Use of energy by moving object
If gain switching is performed to optimize power and die area, then power and die area are reduced, but audible artifacts are introduced
Solution Approach 1:
The system uses feedback mechanisms to monitor the input signal level and dynamically adjust the switching between signal paths. This feedback control ensures smooth transitions and maintains signal integrity, preventing the introduction of audible artifacts while optimizing power consumption.
Solution Approach 2:
The patent implements preliminary gain adjustment and signal conditioning in each path before the switching point. This preliminary action ensures that signals are properly prepared for their designated path, reducing distortion and artifacts during the transition between paths.
Data Source
AI summary
Exemplary multipath digital microphones described herein can comprise exemplary embodiments of automatic gain control and multipath digital audio signal digital signal processing chains, which allow low power and die size to be achieved as described herein, while still providing a high DR digital microphone systems. Further non-limiting embodiments can facilitate switching between multipath digital audio signal digital signal processing chains while minimizing audible artifacts associated with either the change in the gain automatic gain control amplifiers switching between multipath digital audio signal digital signal processing chains.