LM48580: Input capacitors needed when using a HPF for the audio inputs?

Stephan P

Part Number: LM48580

Hi all,

I'm currently using the LM48580 to drive a piezo speaker and this is working quite well. However, I'd like to implement a differential high pass filter before the amplifier and was wondering if in this case the 0.47uF input capacitors Cin that are shown in the datasheet of the LM48580 can be omitted since the HPF will sufficiently block any DC from the inputs?

Here is the filter that I have in mind:

Thank you in advance for your help,

Stephan

over 6 years ago

0 Luis Fernando Rodriguez S. over 6 years ago

TI__Guru* 84915 points

Hi, Stephan,

There is no problem using the filter that you showed above. As you mentioned, the capacitor is only used to block DC-component form the analog input. A high-pass filter like the one that you are intending to use should be enough to block the DC component too.

Please let me know if you have additional questions or comments about this.

Best regards,
Luis Fernando Rodríguez S.

0 Stephan P over 6 years ago in reply to Luis Fernando Rodriguez S.

Prodigy 220 points

Thank you, that answers my question.

Best regards,

Stephan

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LM48580: Input capacitors needed when using a HPF for the audio inputs?