A 1microW 85nV/ radicalHz pseudo open-loop preamplifier with programmable band-pass filter for neural interface...

Area of Science:

• Electronics
• Biomedical Engineering
• Signal Processing

Background:

• Neural interface systems require low-power, low-noise amplifiers for signal acquisition.
• Existing amplifiers often struggle to balance power consumption, noise performance, and bandwidth programmability.

Purpose of the Study:

• To develop an energy-efficient pseudo open-loop amplifier with a programmable band-pass filter for neural interface systems.
• To achieve the lowest noise efficiency factor in differential topologies for neural amplifiers.

Main Methods:

• Designed a pseudo open-loop amplifier architecture.
• Integrated a programmable switched-capacitor band-pass filter.
• Utilized a 0.25microm CMOS technology for fabrication.

Main Results:

• Achieved an energy consumption of 400nA at a 2.5V power supply.
• Measured input-referred noise of 1.69microV(rms) and thermal noise of 85nV/√Hz.
• Demonstrated a programmable bandwidth from 138 mHz to 2.2 kHz.
• Obtained a noise efficiency factor of 2.43, the lowest reported for differential topologies.

Conclusions:

• The developed amplifier offers superior energy efficiency and noise performance for neural interfaces.
• Programmable bandwidth allows adaptation to various neural signal acquisition requirements.
• The compact design and low power consumption make it suitable for implantable and wearable neural systems.