An implantable mixed-signal CMOS die for battery-powered in vivo blowfly neural recordings

Drakakis, E. M.; Krapp, H. G.; Huang, Jiaqi V.; Yue, Xicai

Abstract

© 2018 A mixed-signal die containing two differential input amplifiers, a multiplexer and a 50 KSPS, 10-bit SAR ADC, has been designed and fabricated in a 0.35 μm CMOS process for in vivo neural recording from freely moving blowflies where power supplied voltage drops quickly due to the space/weight limited insufficient capacity of the battery. The designed neural amplifier has a 66 + dB gain, 0.13 Hz-5.3 KHz bandwidth and 0.39% THD. A 20% power supply voltage drop causes only a 3% change in amplifier gain and 0.9-bit resolution degrading for SAR ADC while the on-chip data modulation reduces the chip size, rendering the designed chip suitable for battery-powered applications. The fabricated die occupies 1.1 mm2 while consuming 238 μW, being suitable for implantable neural recordings from insects as small as a blowfly for electrophysiological studies of their sensorimotor control mechanisms. The functionality of the die has been validated by recording the signals from identified interneurons in the blowfly visual system.

• Journal Article Type: Article
• Acceptance Date: Jan 25, 2018
• Publication Date: Apr 1, 2018
• Deposit Date: Feb 1, 2018
• Publicly Available Date: Feb 22, 2018
• Journal: Microelectronics Journal
• Print ISSN: 0026-2692
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 74
• Pages: 34-42
• DOI: https://doi.org/10.1016/j.mejo.2018.01.022
• Keywords: implantable neural recording, blowfly, CMOS neural amplifier, SAR ADC
• Public URL: https://uwe-repository.worktribe.com/output/876655
• Publisher URL: https://doi.org/10.1016/j.mejo.2018.01.022
• Contract Date: Feb 1, 2018