Electronics Handbook/Circuits/Low-pass Filter

Low-pass Filter

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A low-pass filter has a stable voltage at low frequencies and increasing voltage at high frequencies.

Low-pass Filter , LR Configuration

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Picture

Vo/Vi

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Frequency Response

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ω = 0 .  
ω =   .  
ω = 00 .  
 

LR has a stable voltage at low frequencies and increasing voltage at high frequencies.

Low-pass Filter , RC Configuration

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Vo/Vi

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  với
 

Frequency Response

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RC has a stable voltage at low frequencies and increasing voltage at high frequencies.

Summary

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  1. Low-pass filters have a stable voltage at low frequencies and increasing voltage at high frequencies.
  2. Low-pass filters can be constructed from RC or LR.
  3. Low-pass filters have a general formula:
  . T = RC =