TPA6112A2: TPA6112A2 MUTE/UNMUTE function noise?

Hi, John

This makes me think in a pop issue in your device.

I would recommend to try adding the DC-Blocking capacitors in the analog inputs of your device. It seems that they are not placed as suggested in the typical application schematic (capacitors C3 in the picture).

Please let me know if the problem persists.

Best regards,
Luis Fernando Rodríguez S.

There is already C3 added to the circuit, and the problem still exists.

The distance from C3 to TPA6138A2 is about 20mm. Does this have any effect? Or is the capacitor closer to TPA6138A2, can the problem be improved?

Finally, I would like to ask, when the MUTE switches to UNMUTE, how long does the internal Audio amplifier turn on?

OPAMP_TPA6138_sch_layout .pdf

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Hi, John,

Thank you for providing the details about the DC-coupling capacitors. Your schematic seems to be correct. Regarding your question about the the time that the internal audio amplifier takes to turn on after the MUTE switches to UNMUTE, usually this takes no more than 1ms.

I have some questions about your circuit:

- If you isolate the TPA6138A2 from the rest of components (I mean, if you just power up the TPA6138A2 and disconnect the inputs from the other devices) do you still have this issue when you mute or unmute the device?
- Do you see any variation on the power supplies when the mute/unmute is applied?
- Is this a constant noise or just a pop noise? Do you have a scope capture of it?

Thank you.

Best regards,
Luis Fernando Rodríguez S.

Hi, John,

Excuse me, could you take a look at the responses of my last post? Do you have any feedback on this?

Best regards,
Luis Fernando Rodríguez S.