A Fully Integrated 1.13 NEF 32-Channel Neural Recording SoC With 12.5 pJ/Pulse IR-UWB Wireless Transmission for Brain Machine Interfaces

Abstract

Monitoring electrical activity from numerous neurons with the help of a high-channel count neural recording system is crucial for the state-of-the-art approaches in neuroscience research and clinical treatment. The performance trade-offs such as channel count, total power consumption, noise, area, and robustness need to be optimized for compatibility in neural signal acquisition system. This work proposes an implantable 32-channel neural signal acquisition system-on-chip (SoC), which includes 32 neural amplifiers, an analog multiplexer (MUX), an analog-to-digital converter (ADC), and an impulse radio ultra-wide band (IR-UWB) transmitter designed using 180 nm CMOS process. The neural amplifier allows to detect local field potentials (LFP) and action potentials (AP) separately in a programmable gain-bandwidth setup. It achieves 48 dB gain within the 0.2–345 Hz for LFPs and a gain of 59.7-dB within the 310–20.7-kHz frequency range for APs. A 10 bit SAR-ADC is designed with reconfigurable sampling rate of 10–40-kSps achieving an FOM (Figure-of-Merit) of 629-fJ/step. The designed IR-UWB transmitter can transmit data at 100-Mbps data rate with an energy efficiency of 12.5-pJ/pulse. The proposed system shows a promising reconfigurable multi-channel neural signal recording paradigm for neuroscience research and Brain Machine Interfaces (BMIs) applications.

Keywords

• Multi-channel neural amplifier
• SAR-ADC
• reconfigurability
• IR-UWB transmitter