• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 30 subscribers
  • Views 852 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPA6130A2: Minimize/eliminate digital noise from I2C signal in audio output

Itcoil
Prodigy 20 points
Part Number: TPA6130A2

I would like to know any recommended steps (schematic and/or layout) for keeping audible digital interference from happening on the audio output of this part while an I2C signal is being sent to it.

  • 0
    TI__Guru* 84915 points

    Hi, itcoil,

    Welcome to E2E and thank you for your interest in our products!

    When designing an audio device with analog and digital stages, it is important to separate both activities since it may result in noise issues from digital side to analog portion, as you clearly mentioned in your post.

    We strongly recommend to separate the digital activity with ground traces or planes. This is a good practice to avoid parasitic effects from the I2C lines into the analog lines. The ground traces should be between the digital PCB traces and the analog ones. Even it is recommended to include ground traces between each digital line.

    Also, in case you have the TPA6130A2 sharing the ground connection with another device, you would need to verify that this other device doesn't have switching activity (PWM, Class-D, delta-sigma converters). This may affect the device performance. So, you would need to separate both ground planes and join them with single 0-ohm resistors or PCB traces. This separation would be enough to mitigate the noise issues from device to device.

    I hope this helps you. Please let me know if you have additional questions or comments.

    Best regards,
    Luis Fernando Rodríguez S.

  • 0 in reply to Luis Fernando Rodriguez S.
    Prodigy 20 points

    This would be for the case where the TPA6130A2 is getting its signal from the outputs of a PCM5102APWR which is getting its I2S signal from a single board computer but the I2C signal controlling the TPA6130A2 is coming across external wires to a header connected to the circuit with the TPA6130A2.

  • 0 in reply to Itcoil
    TI__Guru* 84915 points

    Hi, Itcoil

    Thank you for the details on this. In that case, you would need to try to design the layout to have the digital lines on one plane (digital plane) and the rest of activity on another ground plane (analog plane). This would separate both activities. Usually, the I2S and I2C activities have high frequency content that could be introduced as noise signals on the analog side. If the analog inputs are affected by these parasitic effects, there could be risk to amplify the noise in the amplifier.

    So, the best practice for this case is to separate both activities on two different planes and then join the planes with the pcb traces or 0-ohm resistors as I mentioned in the previous post. For more details and tips to mitigate noise issues, please take a look at the document below:

    http://www.ti.com/lit/an/slaa749/slaa749.pdf#page=4

    Best regards,
    Luis Fernando Rodríguez S.