Programmable gain amplifiers with DC suppression and low output offset for bioelectric sensors

Area of Science:

• Bioelectric signal processing
• Analog circuit design

Background:

• DC-offset and DC-suppression are critical in bioelectric amplifiers but often lack detailed analysis.
• Factors like programmable gain, high-pass filter cut-off frequencies, and capacitor issues complicate DC management.

Purpose of the Study:

• To propose and test a new intermediate stage for bioelectric amplifiers to resolve DC-offset problems.
• To achieve a constant low output offset independent of gain and cut-off frequency settings.

Main Methods:

• Developed a novel intermediate stage featuring a programmable gain amplifier (PGA) with integrated DC-rejection and low output offset.
• Implemented selectable cut-off frequencies ranging from 0.016 to 31.83 Hz.
• Embedded capacitor deblocking functionality within the circuit design.

Main Results:

• The proposed PGA stage effectively addresses DC-offset issues in bioelectric amplifiers.
• Achieved consistent low output offset across various gain and cut-off frequency selections.
• Demonstrated successful capacitor deblocking within the integrated design.

Conclusions:

• The novel intermediate stage provides a robust solution for managing DC-offset in bioelectric amplifiers.
• This design enhances signal integrity by maintaining a stable low output offset, crucial for accurate bioelectric measurements.