thermal drift on the ADV7513

HI,

I do not know of any specific thermal drift issues with the ADV7513.  What exactly drifts in the AD9889B that lasts only a few frames?

Between 1 to 3 minutes after turn on the out put of the AD9889B shifts from 148.5MHz to ~155MHz.  This is with the input clock constant at 148.5MHz.  After a few frames the output frequency returns to normal.  The frequency change is enough to cause a monitor to drop out.  This only happens when started from cold (75 F or less)

This sounds really strange since the TMDS clock is locked to the input clock and only abrupt changes in the PVDD (AVDD) voltage should have these effects.  You might monitor PVDD during this drift to see if any strange is happening with it.

Let me ask around and see if anybody else has seen this before.

I have monitored PVDD, no change.  Voltage in spec, 8mVp-p noise.

Can this problem be associated with the PLL gear-shifting problem mentioned in the AD889B to ADV7513 change over guide?

I do not know.  I am asking someone who would know if that's the problem.  I'm surprised it happens 1-3 minutes after start up which points to something thermal.

Any update?  I am on a deadline.  If I have the same problem with the ADV7513 as the AD9889B, I will need to update my resume.

Still trying to get an answer.  Hopefully the guy is back in the office from travel.

Hi Hank,

ADV7513 is a much newer TX design than the AD9889B and has a lot of improvements over the AD9889B.

If you want to check out its performance you can get an Eval board and play around with it. I'm not aware of any drift issues with the ADV7511, ADV7511W, ADV7513 TXs.

The eval board is available in two flavors, HDCP and non-HDCP enabled. We cannot sell a HDCP enabled board to anyone who is not a HDCP adopter due to licensing restrictions on HDCP keys.

* EVAL-ADV7612-7511 (HDCP-enabled receiver)

* EVAL-ADV7612-7511P (non-HDCP-enabled receiver)

The ADV7513 is more or less a pin reduced ADV7511 and there is scripts to run the ADV7511 like a ADV7513 for the eval board.

Mike