Sallen-Key BandPass Analog Filter Frequency Response & Transfer Function

[@STEMprof]

Thanks for watching. For more Analog and Digital Signal Processing & Circuit examples please see: Butterworth Analog Filter Design with Op Amp kzbin.info/www/bejne/iXqwmGiKhK6aqKM Digital Filter Cascade Implementation Example kzbin.info/www/bejne/iWbIp2dpgLZ9o7s Universal Analog Filter Design kzbin.info/www/bejne/aHuQYaCpjb94aNE Digital Filter Design using MATLAB filter Designer Tool kzbin.info/www/bejne/moS9nqyjfMZmjdE Sallen-Key Filter Design Tutorial: LPF, HPF Frequency Response, Damping Factor kzbin.info/www/bejne/gai4n4SOl9Bqna8 How to find Bode Plot, Freq Response, Transfer Function of Analog Filters kzbin.info/www/bejne/rIupnIObecZkfpo Lowpass Butterworth Filter: kzbin.info/www/bejne/i6umm56tpt5gb9k Digital Filter: Direct Form vs Transpose Form kzbin.info/www/bejne/m5zZimCZqbxpgNU Laplace Transform Example and S-domain circuit analysis: kzbin.info/www/bejne/pqSbf2iKhbKSp7c Op Amp circuit Bode Frequency plot kzbin.info/www/bejne/eH25q6irpqafkNU Analog Logarithm Computer kzbin.info/www/bejne/iKGudqRrjN6igsk Op Amp Amplifier with Electronic Gain Control kzbin.info/www/bejne/hKCxmISml89qbbs Analog Computer solves Differential Equation kzbin.info/www/bejne/e3_UZGx7mtiZhtk Voltage Regulator Design with Op Amp and BJT Transistor kzbin.info/www/bejne/qHqcl2ljed6LrrM Analog Computer to Raise Signal to power n kzbin.info/www/bejne/f4a3nXV-Zrqll6c Triangle Oscillator Op Amp circuit kzbin.info/www/bejne/gHeYhqOVmNp_b80 Differential Equation Solver Analog Circuit kzbin.info/www/bejne/iGS7ZnSPg796e6s Complex Sinusoid Oscillator kzbin.info/www/bejne/fYm1maCtorhokM0 Sawtooth Oscillator Design kzbin.info/www/bejne/aJa4pHqGm9aVjZY Full-Wave Rectifier circuit example kzbin.info/www/bejne/enutfoGLYqiMmck Sawtooth Waveform Generator design with OpAmp, JFET, BJT kzbin.info/www/bejne/a6uriYeuYrufaJI For more Digital Signal Processing and DSP examples please see kzbin.info/aero/PLrwXF7N522y6cSKr0FmEPP_zQl011VvLr For more analog circuits and signal processing examples see: kzbin.info/aero/PLrwXF7N522y4c7c-8KBjrwd7IyaZfWxyt I hope these Analog and Digital Circuit design and analysis videos are useful and interesting.🙏

[@STEMprof]

You are welcome. Thank you for the comment.

[@geneglick3428]

Hello. Nice video. Thanks. I notice a small difference in your Sallen-Key topology and others. After some research, I see that the Sallen-Key relies on a buffered copy of signal, in this case, at the "+" terminal of the opamp. Yours is functionally equivalent to those others with unity gain, I believe. If more gain is desired, the alternate topology is used. I think the analysis is similar in both cases.

[@STEMprof]

You are welcome! And thanks for sharing your observations and insights. Here is another example that you might find interesting, Sallen-Key Filter Design Tutorial: LPF, HPF Frequency Response, Damping Factor kzbin.info/www/bejne/gai4n4SOl9Bqna8

[@kifunyemichael5259]

What if my high pass has a a cut off frequency of 0.5Hz and lpf a cut off of 100 Hz, what would the values be?

[@STEMprof]

While F=0.5 Hz is a considerably low cut-off frequency for the highpass filter, using equations explained at 18:40 , with Damping Factor set to 1/sqrt(2) we get R1=2*R2 and 2*pi*F=1/(C*sqrt(R1*R2)) . Hence we get R2 = 1/(2*pi*1.41*F*C) , if we set F=0.5 Hz and say C=1.2uF then we get R2=200 kOhm , R1=400 kOhm. Now, similarly, for lowpass filtering portion of this Sallen Key Filter, using equations explained at 26:35 , with R=100kOhm we can derive C1=11nF, C2=22nF. I hope this is helpful.

[@rudygomez6996]

I dont understand how you got equation w^4/(w^4+wn^4), at minute 17:00.

[@STEMprof]

Thanks for watching and your interest in this Bandpass Sallen-Key Filter Design video. With damping factor (zeta) set to 1/sqrt(2) substitute s=jw in H(s) and simplify the resulting algebraic expressions to arrive at the equation at 17:00. Please watch this additional example Butterworth Analog Filter Design with Op Amp kzbin.info/www/bejne/iXqwmGiKhK6aqKM . I hope this is helpful.

[@novrain7474]

whats our gain equation in this video?

[@STEMprof]

Watch minutes 16:45 and 24:00 for the two frequency Response (transfer function) corresponding to the cascaded first stage and second stage. One can find the gain at any target frequency using the equations discussed. To further help, here are two related filter videos: Sallen-Key Filter Design Tutorial: LPF, HPF Frequency Response, Damping Factor kzbin.info/www/bejne/gai4n4SOl9Bqna8 Butterworth Analog Filter Design with Op Amp kzbin.info/www/bejne/iXqwmGiKhK6aqKM

[@2001pulsar]

Not helpful unless you did some special engineering math at university. w, z, x, m... hmmm

[@STEMprof]

Thanks for watching & your interest. Deriving Transfer function of filter & Frequency Response require Circuit S-domain analysis, computing Cutoff Frequency & Damping Factor to select components properly. For more examples please see kzbin.info/aero/PLrwXF7N522y4c7c-8KBjrwd7IyaZfWxyt I hope these Analog and Digital Circuit design and analysis videos are useful and interesting.

[@2001pulsar]

@@STEMprof thanks, yes the video was interesting, but I feel the maths could be simplified to cater to a wider audience. By using frequency in hertz, for example, would make the design more "calculable" for a non- engineer person, such as myself.

[@STEMprof]

@@2001pulsar You are welcome. Thanks for watching, sharing your thoughts and your interest. To further help, please watch the video kzbin.info/www/bejne/iXqwmGiKhK6aqKM which is Butterworth Analog Filter Design with Op Amp. I hope this is helpful.