Rc phase shift to oscillate at 10kHz

AnalogKid

Joined Aug 1, 2013
10,987
But is the IC i used correct? Or do i change it?
Many parts, including the venerable LM324 and 358, regularly exceed their published specifications. So, will the circuit work? Probably yes, and probably every time. But will it work *by design*? No.

To determine if the IC is adequate, compare two numbers.

First, calculate the forward gain needed for the circuit to oscillate. To that, add an additional 20 dB as a rule-of-thumb minimum gain needed to close the negative feedback loop. Multiply that by the frequency of interest (10,000). This is the minimum gain-bandwidth product needed to consider an IC for this circuit.

Second, look up the gain-bandwidth specification on the IC datasheet. Compare it to the result of step 1.

Another approach is to calculate the gain needed for the circuit to oscillate. Then locate this gain and the frequency of interest on the datasheet open-loop gain plot. If that point is not at least 20 dB below the plot line, then the chip probably will not work well.

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MrAl

Joined Jun 17, 2014
11,389
Hello,

You might get away with that cheaper op amp, but if you get too much distortion try lowering the output peak voltage. The op amp slew rate can probably keep up with a 10kHz signal as long as it is not too high in amplitude. We can crunch some numbers though if you like.
 
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