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PCM1864: AGND&DGND single-point grounding

lei liu
Prodigy 20 points
Part Number: PCM1864

Hello  TI's experts:
Now I use the audio codec PCM1864，I have a few questions：

1、In the datasheet, the digital ground and the analog ground are directly connected together and there is no single-point grounding. Is it OK?

2、There are two options for the duty cycle of LRCK, 50% and 1/256. Will these two options affect the audio characteristics?


3、 Which register is the duty cycle of BCLK set? Now，I found that BCLK duty cycle is not 50%, will it cause abnormal recording?

Thanks

  • 0
    Genius 3945 points

    1. Always tie the "analog" and "digital" grounds together -- connect the pins to the same ground plane. Route your digital signals away from the analog signals.

    2. The 1/256 LRCLK mode is for certain DSP interfaces. What data interface are you using?

  • 0 in reply to Andy Peters
    Prodigy 20 points

    Hi:

    1、 Tie the "analog" and "digital" grounds together directly or through a 0 ohm resistor？

    2、I recorded 2 audio files. When the background sound is relatively small, the noise floor is very small, but there is an obvious "bububu" noise in the effective sound segment. Please help analyze the possible reasons?

    Thanks

  • 0 in reply to lei liu
    TI__Mastermind 23030 points

    Are you using your own PCB Layout ? 

    Please send us your schematic as well as Register settings

  • 0 in reply to lei liu
    Genius 3945 points

    " Tie the "analog" and "digital" grounds together directly or through a 0 ohm resistor?"

    Pour one ground plane. Connect the AGND and DGND pins to that plane.