Microphone VAD Detection Power Management
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Solution Overview
Problem
Current voice activity detection (VAD) approaches in microphones consume excessive power, leading to reduced standby times in mobile devices, which is a concern for user satisfaction and device performance.
Innovation Solution
A microphone system with a VAD algorithm that operates in multiple power modes, utilizing a low clock frequency and interrupt signals to minimize power consumption, allowing for efficient voice detection and switching between low-power VAD mode and high-power full system operation, with an internal on-chip oscillator and external clock synchronization for optimal power management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional VAD approaches are used in microphones, then voice detection functionality is achieved, but power consumption increases significantly
Solution Approach 1:
The system dynamically switches between two operational modes: a low-power VAD mode using an internal oscillator at reduced clock frequency, and a full-performance mode using an external clock at higher frequency. This dynamic adaptation allows the microphone to optimize power consumption based on operational requirements while maintaining voice detection capability.
Solution Approach 2:
The patent changes the clock frequency parameter by selecting between an internal oscillator (lower frequency) for VAD operations and an external clock (higher frequency) for full system operations. This parameter change enables the system to reduce power consumption during voice activity detection while preserving the ability to achieve accurate voice recognition when needed.
2Use of energy by moving object
If the microphone operates in low-power mode with internal oscillator, then power consumption is reduced, but system performance and accuracy decrease
Solution Approach 1:
The system segments the voice processing task into two distinct stages: first, a low-power VAD stage using the internal oscillator to detect voice activity, and second, a high-performance recognition stage using the external clock when voice activity is detected. This segmentation allows the system to achieve accurate voice recognition only when necessary, while spending most time in low-power mode.
Solution Approach 2:
The VAD function performs preliminary detection of voice activity before initiating full voice recognition processing. By using the internal oscillator to first determine whether voice is present, the system avoids activating the power-intensive external clock and full processing chain unless actually needed, thus preserving accuracy while minimizing power consumption.
3Reliability
If the system continuously monitors for voice activity with high accuracy, then detection reliability is improved, but power consumption increases
Solution Approach 1:
The system employs periodic monitoring using the internal oscillator to detect voice activity intervals. Rather than continuously operating at full performance, the microphone periodically checks for voice presence using the low-power internal clock, and only activates the external clock when voice activity is detected, thereby maintaining detection reliability while reducing overall power consumption.
Data Source
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AI summary
A microphone includes a microelectromechanical system (MEMS) circuit and an integrated circuit. The MEMS circuit is configured to convert a voice signal into an electrical signal, and the integrated circuit is coupled to the MEMS circuit and is configured to receive the electrical signal. The integrated circuit and the MEMS circuit receive a clock signal from an external host. The clock signal is effective to cause the MEMS circuit and integrated circuit to operate in full system operation mode during a first time period and in a voice activity mode of operation during a second time period. The voice activity mode has a first power consumption and the full system operation mode has a second power consumption. The first power consumption is less than the second power consumption. The integrated circuit is configured to generate an interrupt upon the detection of voice activity, and send the interrupt to the host.