Questions tagged [sallen-key]
For questions about the Sallen-Key filter topology. Use in conjunction with related tags such as "filter", "active-filter", "high-pass-filter", and/or "operational-amplifier", as applicable.
84 questions
0 votes
3 answers
240 views
Op-amp biasing not working as intended
This is regarding the biasing of a second order Sallen-Key low pass filter. The filter seems to work fine when I use a sinusoidal input in LTSpice and produces an output centered around 1.65 V. ...
- 11
2 votes
2 answers
206 views
Haptic Feedback Circuit
This is my setup for a project I'm working on regarding haptic feedback from my guitar. It takes audio in and splits the signals into those that can be detected by the skin effectively (up to around ...
- 421
3 votes
2 answers
233 views
Initial conditions of this active Sallen-Key circuit are confusing me
I was given a lab assignment where I was to analyze this op-amp-based Sallen-Key circuit below: I did the nodal analysis and got my characteristic equation. What's seriously bugging me is how to ...
- 281
2 votes
2 answers
184 views
Use of Inductors in Low Pass Filter
Sallen Key Configuration Equation 3.6 shows the general transfer function of the Sallen-Key configuration shown. Equation 3.7 shows the standard form of a second order low pass filter. My notes ...
- 209
1 vote
2 answers
85 views
AC Analysis Phase in a Sallen Key Lowpass
Hi im trying to do Ac Analysis in Kicad and encountering some problems. I have a a low pass Sallen key cascaded two times to create a steeper slope. My opamp is working with single supply from 0V to +...
2 votes
2 answers
374 views
How do I create a DC Bias tee to stop the AC and DC from interferring with each other?
I'm working on building wireless speakers. After going through the active lowpass filter stage I added a second amplification stage to get up to the voltage level of my speakers I was using. However, ...
8 votes
3 answers
1k views
Pros & cons of Sallen-Key vs. double RC cascaded stages low pass filter topologies
Here are two possible topologies to implement an active non inverting second order low pass filter, namely Sallen-Key and two cascaded RC stages. Both circuits have the same transfer function: $$H(j\...
- 264
1 vote
1 answer
125 views
Needing help with a design assignment
For a class I am taking we were assigned to create a circuit where we are given a signal with lots of noise, design a circuit that will cutoff any frequency higher than 1.87 kHz with a sharp roll-off. ...
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