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TPS84A20: None

Part Number: TPS84A20

Hi,

TPS84A20 has two types of ground, PGND and AGND. According to the datasheet, PGND is the return current path for the power stage of the device and AGND is the zero volt reference for the analog control circuit. In the Layout Consideration, it is recommended to keep AGND and PGND separate from one another. Should they be connected to a single point somewhere in the PCB? I also checked the TPS84A20EVM board, there is a zero jumper to tie AGND and PGND together but it is not populated. Other than that could not find anywhere AGND and PGND tied to each other. Could you tell me if the two grounds should be tied together? Is it addressed in the datasheet?

Thank you,

Yong

  • The AGND and PGND connection is made internal to the device. It is not recommended to connect them again on the PCB.

    The Layout Considerations on page 26 of the datasheet says to keep AGND and PGND seperate from one another.

  • Hi,
    Thank you very much for the quick response!
    Is it addressed somewhere in the datasheet? I could not find it anywhere in the datasheet.
    Also there are two AGND pins. According to datasheet, they are not connected together internal to the device and must be connected to one another on the PCB. Is that true? I am trying to understand how they are connected to PGND internally. Is only one AGND pin tied to PGND internally?

    Thanks,

    Yong
  • Yes, it is included in the Layout Considerations section on page 26 of the datasheet.
    The 2 AGND pins must be connected to one another using a AGND connection on your PCB. Yes, only one of the AGND pins is connected to PGND internal to the device.
  • What I mean is I could not find anywhere in the datasheet that PGND and AGND are connected internally. I would like it is clearly addressed in the datasheet. That will make the layout consideration easily understood. Otherwise, we will probably tied them together in the PCB.