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TeMa_2997106
Level 6
Level 6
10 likes received 10 solutions authored 250 replies posted

Does the impedance of the clock input terminal change after a while after the power is turned on?

The voltage on the input clock drops a little (from 3.3V to 3V).
I don't know why it happens. I don't even know where to check.

We have made several boards and all of them have this phenomenon. However, this symptom does not appear even though the circuit is the same on the previous board.

Thanks,
Tetsuo

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1 Solution
MallikaK_22
Moderator
Moderator
Moderator
250 solutions authored 500 replies posted 250 replies posted

Hi Tetsuo,

Please confirm if you are referring to the XIN voltage level.

Are you following the crystal recommendations?

I didn't understand the last part. Was this issue not seen in previous revisions of the board but is seen now? 

Regards,

Mallika

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2 Replies
MallikaK_22
Moderator
Moderator
Moderator
250 solutions authored 500 replies posted 250 replies posted

Hi Tetsuo,

Please confirm if you are referring to the XIN voltage level.

Are you following the crystal recommendations?

I didn't understand the last part. Was this issue not seen in previous revisions of the board but is seen now? 

Regards,

Mallika

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Ajeethkumar
Moderator
Moderator
Moderator
25 likes received 250 sign-ins 50 solutions authored

Hi,

Thanks for posting in Infineon Developer Community!

The impedance will not change after the power is turned on. 

  1. How close is your crystal from the HX2VL chip? Maximum suggested trace length is 1cm
  2. What is the Crystal Drive level? Crystal Drive level should be at least 600uW with accuracy of +/-500 ppm

Thanks,
Ajeeth

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