DP83822HF: How adc works for this IC?

longfei zhang

Part Number: DP83822HF

We met some noise problem that is crc error usually reported and even disconnect when servo motor current becomes big.no isolation between dc bus bar ground and DP83822HF ground.

so i doubt that adc sampling may has wrong sampling for nosie disturbing and i am curious about how adc works for this ic,where power supply is from for adc，is there any filter for adc?

do you have comments for other cause of this issue?

over 5 years ago

0 longfei zhang over 5 years ago

Intellectual 410 points

0 Justin Lazaruk over 5 years ago in reply to longfei zhang

TI__Expert 7040 points

Hi Longfei,

Can you provide more details about the noise issue that you are seeing? The block diagram above is a simplified version of the digital logic in the PHY, and there are many signal conditioning and filtering blocks between the Ethernet pair and the ADC.

What you have described is commonly due to EMI/EMC performance of the system. Can you provide the schematic information and describe if the MDI layout guidelines are followed in the DP83822 datasheet?

Regards,
Justin

0 longfei zhang over 5 years ago in reply to Justin Lazaruk

Intellectual 410 points

I find it is TX RX signal problem, EMC from swithing coupled into these trace,thanks .

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DP83822HF: How adc works for this IC?