Operational Amplifiers Flashcards
What is an Operational Amplifier?
A high-gain dc amplifier that has extremely high
voltage gain, high input impedance, and low output impedance
What ideal characteristics does an op-amp have?
- Infinite voltage gain
- Infinite input impedance
- Zero output impedance
- Infinite slew rate
What is an op-amp made up of?
- Differential amplifier (input stage)
- Voltage amplifier (gain stage)
- Push-pull amplifier (output stage)
What is Input offset current (Ios)?
The difference between the input bias currents; expressed as an absolute value
Ios = |I1 - I2|
Define Output impedance?
The resistance of the op-amp as seen by the load (i.e., the impedance of the output terminal)
Define open-loop voltage gain?
The internal voltage gain of an op-amp that equals the ratio of output voltage to input voltage when there are no external components connected to the component
Define slew rate?
The maximum rate of change of op-amp output voltage in response to a step input voltage; measured with the op-amp connected
What is Closed-loop voltage gain?
The voltage gain of an op-amp with negative feedback applied; i.e, the op-amp and an external
feedback network that connects the output to the inverting input
What is an Noninverting amplifier?
An op-amp circuit that has an input signal applied to its noninverting (+) input. A portion of its output is applied back to the inverting (−) input through the feedback network
