TPA6120A2: TPA6120 POP Noise

Jonas

Part Number: TPA6120A2

My customer find POP noise in TPA6120. The schematic as below, their schematic is same with EVM except the volume control resister VR201

when VR201 set to max and min value, the pop noise is small can accepted.but VR201 set other value(min<value<max), the noise is very large, beyond the acceptable range.

how do we solve this problem ?

over 6 years ago

0 Ivan Salazar over 6 years ago

TI__Guru** 102215 points

Hi Jonas,

It look like the variation from VR when it is not at its max/min is most likely causing a not balanced input.
One of the keys in terms of pop noise is to have balanced inputs, that's one of the reasons that differential input is preferred when available.
Another important thing for pop noise performance is the offset voltage, TPA6120A2 was optimized for sound quality, not pop performance.

Best regards,
-Ivan Salazar
Applications Engineer - Low Power Audio & Actuators

0 Jonas over 6 years ago in reply to Ivan Salazar

Intellectual 540 points

Hi Ivan:

VR is used to adjust volume, it is needed in headphone. Can we help compensate it to reduce the pop ?

0 Ivan Salazar over 6 years ago in reply to Jonas

TI__Guru** 102215 points

Jonas,

Perhaps adding a previous stage to perform the gain adjust instead of doing it actively on TPA6120A2. Have you tried different values on R801 and R806?

Best regards,
-Ivan Salazar
Applications Engineer - Low Power Audio & Actuators

0 Jonas over 6 years ago in reply to Ivan Salazar

Intellectual 540 points

Hi Ivan:

What value shoud we try about R801,R806 ? Do you advices value ? We didn't try different values before.

0 Ivan Salazar over 6 years ago in reply to Jonas

TI__Guru** 102215 points

Jonas,

I was just thinking on higher resistor values. Have you tried something else during this time?
It's been a while since last communication, do you still need support for this?

Best regards,
-Ivan Salazar
Applications Engineer - Low Power Audio & Actuators

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TPA6120A2: TPA6120 POP Noise