This brief presents a digital capacitive MEMS microphone for speech recognition with fast wake-up feature using a sound activity detector. The proposed microphone wakes up only when an acoustic event within the voice-band occurs using the sound activity detector, which can significantly reduce the average current consumption. All wake-up processes are performed on-chip, which enables the fast wake-up feature to prevent missing keywords. In addition, the proposed deglitching technique is applied to prevent the sound activity detector from responding to non-acoustic signals such as glitch signals. An auxiliary low-dropout regulator is used to further reduce the wake-up time. Our microphone consumes only 16 $\mu \text{A}$ in deep-sleep mode. In active mode, a high-performance readout circuit converts the voice signal into a digital signal. The proposed microphone achieves an A-weighted signal-to-noise ratio (SNR) of 62.8 dBA and an acoustic overload point of 119.4 dB sound pressure level. The readout circuit itself of our microphone, fabricated in a 0.18 $\mu \text{m}$ CMOS process, has an A-weighted SNR of 65.8 dBA.

中文翻译：

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使用声音活动检测器的具有快速唤醒功能的语音识别数字电容式 MEMS 麦克风

本简介介绍了一种用于语音识别的数字电容式 MEMS 麦克风，该麦克风具有使用声音活动检测器的快速唤醒功能。所提出的麦克风仅在使用声音活动检测器的语音频带内发生声学事件时才唤醒，这可以显着降低平均电流消耗。所有唤醒过程均在片上执行，从而启用快速唤醒功能以防止丢失关键字。此外，所提出的去毛刺技术用于防止声音活动检测器响应非声学信号，例如毛刺信号。辅助低压降稳压器用于进一步缩短唤醒时间。我们的麦克风仅消耗 16 $\mu \text{A}$ 在深度睡眠模式下。在主动模式下，高性能读出电路将语音信号转换为数字信号。所提出的麦克风实现了 62.8 dBA 的 A 加权信噪比 (SNR) 和 119.4 dB 声压级的声学过载点。我们麦克风的读出电路本身，以 0.18 $\mu \text{m}$ CMOS 工艺，A 加权 SNR 为 65.8 dBA。