Troubleshooting LM386 Amplifier Noise: Capacitor Value and Behavior Explained

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The LM386 amplifier can produce significant noise at the output, which can be mitigated by adding a capacitor, with a 47uF value being particularly effective. Other capacitor values may not yield the same noise reduction, leading to questions about their behavior. The LM386 is a power amplifier and should not be treated like an operational amplifier; it requires specific connections and configurations. Implementing a Zobel network may also help improve performance and reduce noise. Understanding the proper usage as outlined in the datasheet is crucial for optimal results.
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hi guys,
i'm doing the testing amplifier for my DIY project,
and i using LM386 IC, i found that is a lot of noise at the output.
i saw an example putting a capacitor at the output to reduce the noise, it work!
the value of capacitor is 47uF. it not work well for other value capacitor.
But i not sure why behaviors like that? help please...
 

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miroku said:
hi guys,
i'm doing the testing amplifier for my DIY project,
and i using LM386 IC, i found that is a lot of noise at the output.
i saw an example putting a capacitor at the output to reduce the noise, it work!
the value of capacitor is 47uF. it not work well for other value capacitor.
But i not sure why behaviors like that? help please...

The LM386 is not an opamp. It is a power amp, and you do not connect feedback around it like it was an opamp. Download the datasheet from National Semiconductor's website to see how it should be used.
 
Needs a zobell (spelling?) network.
 

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