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Low temp and the AD9889B

Question asked by HankZ on Mar 11, 2015
Latest reply on Mar 18, 2015 by DaveD

Can you clarify the meaning in datasheet of AD9889BBSTZ-165 (http://www.analog.com/media/en/technical-documentation/data-sheets/AD9889B.pdf):

 

On page 4:

on last page:

1)  What is expected behavior of this HDMI transmitter at -40C? Should it be like after cold start – possible glitches and after heating-up within 10-30 minutes – working without glitches?

We observing glitches even after heating-up, not just after cold startup, and want to understand.

 

2)  What is recommended trace length matching for the data bus for high resolution/frequency mode?

We have 400 psec difference on board, and observed that at -40C a low resolution mode works without glitches while a high resolution one has glitches (blinking or even sometimes black screen). In the datasheet (on page 9), no accurate recommendations about this: “Make sure to match the length of the input data signals to optimize data capture, especially for high frequency modes such as 1080p, UXGA, and double data rate input formats.”

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