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Can current enter op amp?
You can reasonably assume that currents can flow from an input (Va in your diagram) and from the op-amp output (Vo in your diagram). This means you can assume current does not flow into the two op-amp inputs and these can be regarded as high impedances.
What is the current coming out of an opamp?
The current flow into the input leads is zero, so the input impedance of the op amp is infinite. The output impedance of the ideal op amp is zero. The ideal op amp can drive any load without an output impedance dropping voltage across it.
How do you find the current through a feedback resistor?
Due to feedback, the current through the feedback resistor is equal to the sum of these input currents. The output voltage, therefore, is the product of the feedback resistor and the sum of the input current. The individual input currents are equal to the input voltage divided by the respective gain-setting resistor.
What are the golden rules of op amp?
Here are the golden rules of operational amplifiers:
- 1) Infinite Open Loop Gain.
- 2) No current flowing through both of the Inputs.
- 3) Potential Difference between input pins is ZERO.
How does the op-amp respond to voltage?
It is responding depending on the input voltage. For example, when the input voltage is .4V, the op-amp will respond to have the same voltage .4V in his feedback pin. The output of the op-amp turn on and control the MOSFET until the voltage drop across the shunt resistor became .4V. The Ohms law is applied in this scenario.
Which is better a current mirror or an opamp?
In this case, the opamp performs the function of a current mirror circuit, and does so with greater precision and reliability than a simple current mirror ever could. It should be noted that the equation provided in the answer does not directly predict the current through the load, rather it predicts current through resistor R 2.
How to calculate the current through a resistor?
Calculate the current through resistor R 2 in this opamp circuit for several different values of R 2: For each value of R 2, what is it that establishes the amount of current through it? Do you see any practical value for a circuit such as this? This circuit acts like a current mirror, except much more precise.
How are op amps used in an IC?
Same as like LM358, many op-amp ICs have two op-amps in a single package. If the input voltage is too low, the second unused op-amp can be used to amplify the input voltage as required. For the improvement of the thermal and efficiency issues, low on-resistance MOSFETs can be used along with proper heat sink.