Sound Activity Monitor Circuit for Low Power Consumption of Always-On Microphone Applications
Source abstract
Abstract
A novel sound activity monitor (SAM) circuit for low power consumption of always-on microphone applications is presented. To reduce average power consumption, the ultra-low-power SAM is essential and operates a readout integrated circuit (ROIC) in low power mode with silent input or in normal power mode with voice input. A novel SAM with an architecture that does not include an envelope detector is proposed to achieve low power consumption. A new architecture is also proposed to improve MEMS sensitivity by connecting the SAM input to the source follower (SF) output instead of connecting the SAM input to the MEMS port already connected to the SF. In addition, in order to prevent inefficient frequent operation mode conversion, a feature of delaying the transition to the low-power mode after the sound is silenced is implemented. The proposed architecture is designed and verified based on the standard 0.18 µm CMOS process. The SAM, which consists of two-stage amplifiers (OA, AMP2), comparators, and a logic circuit, consumes a 1 µA current. The analog path consisting of SF, OA, and AMP2 in low power mode has a maximum amplification gain of 63 dB and a noise of 72 nVrms/√Hz at 1 kHz.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Analog and Mixed-Signal Circuit Design · Advanced Adaptive Filtering Techniques · Speech and Audio Processing
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Advanced Research Center for Mechatronics Engineering, School of Mechatronics Engineering, Korea University of Technology and Education, Cheonan 31253, Republic of Korea
Funding
National Research Foundation of Korea
References (22)
Show source-provided references
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