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TPS546B24A: TPS546B24A: AVIN bypass capacitor

Part Number: TPS546B24A

Tool/software:

The "Pin Functions" table in the datasheet says AVIN should be bypassed to "AGND". The layout guidelines section, as well as the device calculator spreadsheet, says to bypass to "PGND". Which is it?

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  • Hi Daniel,

    It is critical to bypass AVIN to AGND, as we have done on our EVM layout. As you can see, the AVIN capacitor is tied to an AGND via, which goes to the internal layer (layer 6) and is routed to an AGND via near the AGND pin. There should be a single AGND-PGND connection at the thermal pad. 

    We will make sure to update the description in the layout guideline in our next revision of the datasheet.

    Thank you,
    Tomoya

  • Got it, thanks. 

    FYI, another discrepancy in the documentation -

    13, 14, 15, 16, 17, 18, 19, 20 PGND Power stage ground return. Routing The PGND pin (pin 26) must be directly connected to the thermal pad of the device on the PCB, with a low noise, low-impedance path.   Open pin 26 is AVIN?
  • Nice find! We'll make sure to add that to our list for fixing in the next revision of the datasheet Slight smile