SN65DPHY440SS: The retimer IC will cause the LP-->HS a peak and HS-->LP a bit flip

TAO SUN

When we use the retimer to drive camera MIPI signal, the DB output will have peak as the capture shows:but when camera sensor connect to SOC directly, it does not have .

LP-->HS peak

When the HS exit to LP,the THS-skip window has a bit flip.

bit flip 1

bit flip 0

Are they caused by the IC design bug or the design principle ?

over 2 years ago

0 David (ASIC) Liu over 2 years ago

TI__Guru**** 185921 points

Hi,

Does this happen on a particular lane or on all lanes?

Thanks

David

0 TAO SUN over 2 years ago in reply to David (ASIC) Liu

Prodigy 50 points

It happens on all lanes.

0 David (ASIC) Liu over 2 years ago in reply to TAO SUN

TI__Guru**** 185921 points

Hi,

The scope waveform looks to be single ended measurement, can you do a differential measurement? There is a dip at the DPHY440 input as shown below. Depends on the threshold of the dip, I wonder if the dip would be seen by the DPHY440 as a valid switching and this is why you saw the bit flip at the output.

For the peak issue, are you seeing any functional issue?

Thanks

David

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SN65DPHY440SS: The retimer IC will cause the LP-->HS a peak and HS-->LP a bit flip