An Ultra-low-power 28nm CMOS Dual-die ASIC Platform for Smart Hearables

This paper presents an ultra-low-power dual-die platform for (medical) smart hearables. It pairs two custom ASICs: i) Blackghost - a 28nm CMOS near-threshold-V _DD powered and highly integrated SoC with embedded PMU, MCU, 16-issue DSP engine and hardened audio sub-system island; ii) DIRAC - a 28nm CMOS always-on voiceband RF & mixed-signal audio codec frontend. With ~90dB of dynamic range, DIRAC codec consumes <;200μW of total power. For fast wakeup, sleep and standby of Blackghost, DIRAC also features low latency microphone activity detection (MAD) and TX-RX cross fading scheme. This dual-die platform enables miniaturized hearable devices capable of running emerging audio algorithms like deep learning at an extremely low enerzy budget.