A 23-μW Keyword Spotting IC With Ring-Oscillator-Based Time-Domain Feature Extraction
Abstract
This article presents the first keyword spotting (KWS) IC which uses a ring-oscillator-based time-domain processing technique for its analog feature extractor (FEx). Its extensive usage of time-encoding schemes allows the analog audio signal to be processed in a fully time-domain manner except for the voltage-to-time conversion stage of the analog front-end. Benefiting from fundamental building blocks based on digital logic gates, it offers a better technology scalability compared to conventional voltage-domain designs. Fabricated in a 65 nm CMOS process, the prototyped KWS IC occupies 2.03mm$^{2}$ and dissipates 23 $\mu$W power consumption including analog FEx and digital neural network classifier. The 16-channel time-domain FEx achieves 54.89 dB dynamic range for 16 ms frame shift size while consuming 9.3 $\mu$W. The measurement result verifies that the proposed IC performs a 12-class KWS task on the Google Speech Command Dataset (GSCD) with >86% accuracy and 12.4 ms latency.
- Publication:
-
IEEE Journal of Solid-State Circuits
- Pub Date:
- November 2022
- DOI:
- 10.1109/JSSC.2022.3195610
- arXiv:
- arXiv:2208.00693
- Bibcode:
- 2022IJSSC..57.3298K
- Keywords:
-
- Computer Science - Hardware Architecture;
- Computer Science - Sound;
- Electrical Engineering and Systems Science - Audio and Speech Processing
- E-Print:
- 14 pages, 21 figures, 2 tables