A 2.3nJ/frame Voice Activity Detector based audio front-end for context-aware System-on-Chip applications in 32nm CMOS

An audio front-end with Voice Activity Detection (VAD) hardware targeted for low-power embedded SoCs, featuring a 512pt FFT, programmable filters, noise floor estimator and a decision engine has been fabricated in 32nm CMOS. The dual-V
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, dual-frequency design allows the core datapath to scale to near-threshold voltage, where power consumption is less than 50μW. At peak energy efficiency, the core can process audio data at 2.3nJ/frame - a 9.4X improvement over nominal voltage conditions.