Low pass filter circuit questions

In summary, a low pass active filter with a removed capacitor will have a constant gain and no filtering, becoming a circuit constructed around an OP-AMP. This can be supported by the equations that show the frequency dependency of both the capacitor and the op amp. As the frequency is increased towards a very large value, the amplitude will eventually roll off, and this value can be determined by searching for a low pass filter constructed around an OP-AMP. This occurs because the capacitor and op amp both have frequency dependency.
  • #1
thenerveman
1
0

Homework Statement



Why does a low pass active filter give a constant gain and no filtering when the capacitor is removed? What type of circuit does this become? Support your answer with equations.

also

Does the amplitude eventually roll off as the frequency was increased toward to a very large value? how would you determine this value? Why does this occur?

Homework Equations



not sure


The Attempt at a Solution



i don't know where to start really. Our professor is a week behind in his lectures and he assigned this.. I am stuck on these two questoins.
 
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  • #2
Search for a low pass filter constructed around an OP-AMP.
 
  • #3
The capacitor is the frequency dependent component and, as nascent oxygen has indicated, an op amp has some frequency dependency
 

1. What is a low pass filter circuit?

A low pass filter circuit is an electronic circuit that allows low frequency signals to pass through while attenuating or reducing the amplitude of high frequency signals. It is commonly used in audio and communication systems to remove unwanted noise and improve signal quality.

2. How does a low pass filter circuit work?

A low pass filter circuit works by using a combination of resistors, capacitors, and inductors to create a frequency-dependent voltage divider. This means that the output voltage of the circuit is determined by the input frequency, with lower frequencies passing through relatively unaffected and higher frequencies being attenuated.

3. What types of signals are typically filtered using a low pass filter circuit?

Low pass filter circuits are commonly used to filter audio signals, such as music and speech, as well as radio frequency (RF) signals in communication systems. They are also used in power supplies to reduce high frequency noise.

4. What is the cutoff frequency of a low pass filter circuit?

The cutoff frequency of a low pass filter circuit is the frequency at which the output voltage is reduced by 3 dB (half of the original amplitude). This frequency is determined by the values of the components in the circuit and is often referred to as the -3 dB frequency.

5. Are there any limitations to using a low pass filter circuit?

Yes, there are several limitations to using a low pass filter circuit. One limitation is that it cannot completely eliminate all high frequency signals, as some may still pass through with reduced amplitude. Additionally, the cutoff frequency may vary slightly due to tolerance and aging of the components used. Finally, low pass filter circuits can introduce phase shifts in the filtered signal, which may affect the overall performance in certain applications.

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