title: A 515 nW, 0-18 dB Programmable Gain Analog-to-Digital Converter for In-Channel Neural Recording Interfaces.
abstract: This paper presents a low-area low-power Switched-Capacitor (SC)-based Programmable-Gain Analog-to-Digital Converter (PG-ADC) suitable for in-channel neural recording applications. The PG-ADC uses a novel implementation of the binary search algorithm that is complemented with adaptive biasing techniques for power saving. It has been fabricated in a standard CMOS 130 nm technology and only occupies 0.0326 mm(2). The PG-ADC has been optimized to operate under two different sampling modes, 27 kS/s and 90 kS/s. The former is tailored for raw data conversion of neural activity, whereas the latter is used for the on-the-fly feature extraction of neural spikes. Experimental results show that, under a voltage supply of 1.2 V, the PG-ADC obtains an ENOB of 7.56 bit (8-bit output) for both sampling modes, regardless of the gain setting. The amplification gain can be programmed from 0 to 18 dB. The power consumption of the PG-ADC at 90 kS/s is 1.52 μW with a FoM of 89.49 fJ/conv, whereas at 27 kS/s it consumes 515 nW and obtains a FoM of 98.31 fJ/conv .
authors.forename: Alberto
authors.initials: A
authors.lastname: Rodriguez-Perez
authors.forename: Manuel
authors.initials: M
authors.lastname: Delgado-Restituto
authors.forename: Fernando
authors.initials: F
authors.lastname: Medeiro
mesh_terms: D000465:Algorithms; D000703:Analog-Digital Conversion; D000818:Animals; D008251:Macaca; D009044:Motor Cortex / Q000502:physiology; D009474:Neurons / Q000502:physiology; D009482:Neurophysiology / Q000295:instrumentation*