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AM263P4: TRM incomplete regarding ADC DAC loopback

ARJUN RAVEENDRANATH
Prodigy 205 points

Part Number: AM263P4

Tool/software:

Hi all,

I am referring to spruj55b TRM for AM263P4. There is info missing in following pages.

Fig 7-114 is missing and ACQPS value is left blank.

Please provide this info here as an answer rather than updating TRM later.

Thanks,

Arjun

  • 0
    TI__Mastermind 25263 points

    Hello Arjun,

    Thank you for drawing this to our attention. I am looking into this now and will provide you with additional feedback shortly.

    Best Regards,

    Zackary Fleenor

  • +1
    TI__Mastermind 25263 points

    Hey Arjun,

    Design team provided the following feedback:

    ACQPS should be at 3x higher then the typical value. The sampling ADC will have kickback, and since the DAC output is going through a handful of internal switches, it will have a low drive strength. Because of the high impedance sample network, you want to extend the sample time. There isn't an exact value, but the longer the better to give the DAC time to charge the sampling capacitor.

    The ADC Loopback Control Register is located at TOP_CTRL:ADC_LOOPBACK_CTRL (0x50D8 0C80).

    The description in the TRM chapter is currently incorrect. In AM263Px the dedicated Buffered DAC signal is looped back to the ADC (in comparison to the C2000 implementation which uses the DACL signal from CMPSS). An updated diagram and associated descriptive text will be included in the next TRM release.

    Best Regards,

    Zackary Fleenor

  • 0 in reply to Fleenor
    Prodigy 205 points

    Hi Fleenor,

    Thanks a lot for providing this info. looking forward to the next TRM.