TPA2015D1: Regarding the Gain Pin of the TPA2015D1

Part Number: TPA2015D1

Tool/software:

Hi team,

[Issue]
My customer is considering using the TPA2015D1. They are currently in the prototyping phase, but there is a noticeable difference in volume among the prototype boards. (All GAIN pins are set to High and connected to VBAT.)

[Troubleshooting]

  • Based on the above, we suspected that the boards with lower volume might have an open GAIN pin due to a soldering defect. To verify this, we connected a TPA2015D1-EVM to the prototype board and toggled the GAIN jumper, but observed no significant difference in volume or output waveform.
  • We also inspected the BGA soldering using X-ray imaging, but found no evidence of soldering issues.

[Questions]

  • When switching the GAIN pin setting between Low (6 dB), Open (15.5 dB), and High (20 dB), does the internal amplifier stage actually change?
  • Have there been any known issues or insights regarding significant volume variation between boards after assembly?

Best regards,

Kyohei

  • Hi Kyohei,

    it seems the issue is the output volume. the output volume is affected by the input signal, gain setting, AGC(if used) etc.

    from the analyzing step, it seems it is focused on the gain setting. in this case, have you checked the output signal/input signal? if AGC is used, how about the VBAT voltage setting, and the VBAT voltage under test?

    it's better there is some data about the electrical output signal difference. check the AMP input signals, and the vbat voltage level. these data will help to analyze the issue.

    if this is not a HW issue, maybe it could be related to the VBAT voltage by AGC like below:

    Br,

    Wenbin