BIOE 3270 Lecture Notes - Lecture 2: Operational Amplifier, High-Pass Filter, Rc Circuit

• School: University of Manitoba
• Department: Biosystems Engineering
• Course: BIOE 3270
• Professor: Paliwal

Document Summary

Performance (or output) of an op-amp is measured in terms of gain . Gain, the ratio by which a signal is amplified. From an op-amp circuit, we desire infinitely high output. But, gain is limited by: frequency of the input signal. Max output voltage cannot exceed the voltage of the external source. Max. voltage at output will be about 90% of the supply voltage circuit is very unstable because small fluctuations in the input signal become large swings on the output end. Closed loop mode: external components are used to feed a portion of the output back to the inverting input stable circuit and reduced noise. Gain must be controlled for the circuit to have a practical value this is done by adding a resistor ri to the inverting input. On the input end, resistor ri & rf can generate thermal voltages. To nullify these voltages, we need another resistance (rs) added to the other input (non-inverting)