Discussion
The drift in a DC-coupled biomedical amplifier can be minimized by
Answer: A
Drift is minimised by using AC coupling (capacitive coupling).
In a DC-coupled amplifier, slow changes such as electrode polarisation potentials, offset voltages and temperature effects are amplified along with the signal, so the baseline wanders and the stages can saturate. A series capacitor (a high-pass filter, about 0.05 Hz for diagnostic ECG) blocks these DC and very-low-frequency components while passing the signal of interest.
Reducing input impedance would load the electrodes and distort the signal. Large input resistors add thermal noise and bias-current offsets, which make drift worse. Adding feedback capacitance shapes the high-frequency response, not the DC drift.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development