He said second order. Don't give him any more phase shift!Below is the LTspice simulation of a single opamp, 20kHz, 3-pole Sallen-Key type filter with a Butterworth response.
The circuit adds an addition resistor and capacitor at the input to a normal Sallen-Key filter configuration to give a 3-pole, 18dB/octave rolloff above 20kHz for improved noise rejection.
What's the basis for that guess?My guess is that he's hoping to make a switched-mode supply with the feedback controlled by a processor.
Apart from the absence of any other clear information. . .What's the basis for that guess?
Hello,Sorry above I have attached wrong one. Now you can see above post. Yes I have uohm at the source but I used high resistance value to reduces the peak energy at the red curve. If I keep uohm, then see how it will be the graph.
View attachment 247191
Is that because we haven't been told about the double secret NDA we are all supposed to have signed in order for those important details to be revealed?We did explain different types of filter as early as post #2, and 47 posts later he still hasn't told us, nor what his application is.
Could it be a language barrier?We did explain different types of filter as early as post #2, and 47 posts later he still hasn't told us, nor what his application is.
Evidence?Could it be a language barrier?
Not a very good communicator.Evidence?
That happens quite a bit even for people whose first language is English.Not a very good communicator.
Well actually i did not make a definitive statement i posed a question.That happens quite a bit even for people whose first language is English.
I also posed a question and your response would seem to indicate that you have none. I could be wrong, maybe you know or suspect something less than obvious.Well actually i did not make a definitive statement i posed a question.
Since I'm very beginner to electronics. When you asking me more detail of the project I couldn't provide you much information because I don't have any circuits to show you, still now I have a over view of the project only. You guys are asking every time show the circuit. How can I show you if I don't have any circuit to share with you. I understand that you guys are trying to help me but I'm feeling bad since I'm unable to provide you the information. Sorry for the inconvenience guys.I also posed a question and your response would seem to indicate that you have none. I could be wrong, maybe you know or suspect something less than obvious.
May I know why your showing the curve at -3db. Do we need to measure always at -3db?.Below is the LTspice simulation of a single opamp, 20kHz, 3-pole Sallen-Key type filter with a Butterworth response.
The circuit adds an addition resistor and capacitor at the input to a normal Sallen-Key filter configuration to give a 3-pole, 18dB/octave rolloff above 20kHz for improved noise rejection.
View attachment 247197
by Jake Hertz
by Duane Benson
by Aaron Carman