A low-offset analogue front-end IC for multi-channel physiological signal acquisition

Area of Science:

• Biomedical Engineering
• Integrated Circuit Design
• Signal Processing

Background:

• Multi-channel physiological signal acquisition requires precise and low-noise analog front-ends.
• Existing integrated circuits often face challenges with offset voltage and gain variability.

Purpose of the Study:

• To develop a low-offset analog front-end (AFE) integrated circuit (IC) for multi-channel physiological signal acquisition.
• To provide adjustable gains suitable for diverse biomedical applications.
• To offer an optimized solution for portable, high-precision medical devices.

Main Methods:

• Design and fabrication of a mixed-signal IC using SMIC 0.18-mum CMOS technology.
• Integration of low-offset gain programmable instrumentation amplifiers (GPIAs) and high-sensitivity current-to-voltage converters.
• Inclusion of an 8-bit analog-to-digital converter (ADC) for signal quantization.

Main Results:

• Achieved a common-mode rejection ratio (CMRR) of 142 dB and adjustable gain from 31.6 dB to 76.5 dB.
• Demonstrated a low offset voltage (< 80 microV) and excellent ADC linearity (DNL < 0.8 LSB, INL < 1.1 LSB).
• Fabricated IC with a core area of 1.36 mm², low power consumption (348 microW/channel, 1.65 mW for ADC) at 1.8 V.

Conclusions:

• The developed AFE IC provides a high-performance, low-offset solution for multi-channel physiological signal acquisition.
• Its adjustable gain, precision, and low power consumption make it suitable for a wide range of portable and high-precision biomedical applications.
• The integrated design offers an optimal solution for next-generation medical devices.