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How do you choose an op amp when working with high input source resistance?
Explanation: When the op-amp is driven by a high input source resistance, the output and input voltage will not be equal due to error at the input. A remedy to this problem is an op-amp with low input bias current and high slew rate should be chosen as a voltage follower.
What is need of compensated resistor in op amp?
The most common compensation involves adding a resistor [R3] to the standard inverting amplifier to cancel out bias currents [output offset]. The compensation resistor [R3] causes a current, on the positive terminal, equal and opposite to current flowing into the negative terminal.
Why are resistor values in op-amps important?
The op-amp is inverting hence the inverting input is at 0 volts hence the output load IS the feedback resistor and you can’t have this too low or you won’t get the output voltage amplitude. On the other hand, you can’t go too big because the parasitic capacitances of the op-amp will start to reduce gain too much at higher frequencies.
What’s the difference between choosing resistor values like 50ohms and 1ohm?
What’s the difference between choosing resistor values like 50ohms and 1ohm or like let’s say 50kohm and 1kohm. The op-amp is inverting hence the inverting input is at 0 volts hence the output load IS the feedback resistor and you can’t have this too low or you won’t get the output voltage amplitude.
Why do you need a small resistor in an amplifier?
These usually deal with the non-ideal behavior of components (namely Op-Amps), or other design requirements such as power and heat. Small resistors means that you need a much higher current to provide the appropriate voltage drops for the Op-amp to work.
How many resistors in a 10 volt amplifier?
With 10 volt output, only 0.1mA (100uA) output current is needed. And the total resistive_contribution noise, assuming 1MHz UGBW and thus 100,000Hz opamp+resistors bandwidth because of gain of 10X, will be (approximately)