A 266-nW, 4.9-μV_rms Noise, Wideband Neural Recording Amplifier With Folding-Current-Reuse Operational...

Area of Science:

• Biomedical Engineering
• Integrated Circuit Design
• Neuroscience Instrumentation

Background:

• Neural recording requires amplifiers with high sensitivity and low power consumption.
• Existing amplifiers often struggle to balance power efficiency with noise performance.

Purpose of the Study:

• To develop a nano-watt, low-noise, AC-coupled, wideband neural recording amplifier.
• To achieve ultra-low power consumption using novel circuit techniques.

Main Methods:

• Implemented a folded-cascode operational transconductance amplifier (OTA) with folding-current-reuse (FCR) technique.
• Utilized dual voltage supplies for optimized current distribution.
• Fabricated the amplifier in a 180 nm CMOS process.

Main Results:

• Achieved power consumption of 266 nW from 0.4/0.6 V supplies.
• Measured input-referred noise of 4.9 µVrms over a wide bandwidth (0.09 Hz–7.56 kHz).
• Demonstrated 1% THD with a 2.4 mVpp input and 40 dB gain.

Conclusions:

• The FCR technique enables significant power reduction without compromising noise performance.
• The amplifier is suitable for in vitro and benchtop neural recording applications.
• This design offers a promising solution for power-constrained neural interface systems.