lmk04033beval divider issues

user4868114

Other Parts Discussed in Thread: CODELOADER

Hi,

I am currently working with the LMK04033b jitter cleaner and having issues utilizing the divider. I established a configuration using the Clock Design Tool v1.3.5 and configured it via USB with Codeloader v. 4.20.2.
However, whenever I enable dividers on the individual clock outputs the output is seemingly disabled. That is - I see the expected clock without divider in bypass mode, however, as soon as I attempt to divide the output the clock signal disappears. This happens on all the clock outputs. I assume I am missing some vital configuration somewhere, but can't seem to identify it. Does anyone know of a potential solution?

Thank you.

over 9 years ago

0 Timothy T over 9 years ago

TI__Mastermind 28590 points

I think your SYNC* pin is low. SYNC* pin must be high (unasserted) to allow the dividers to run. I think your divider is in SYNC which is why the bypass mode works, but the divided mode doesn't.

73,
Timothy

0 user4868114 over 9 years ago in reply to Timothy T

Prodigy 20 points

Thank you Timothy, that did the trick.
I don't see this information reflected in the datasheet - that SYNC only affects the clock output dividers.

Rami

0 Timothy T over 9 years ago in reply to user4868114

TI__Mastermind 28590 points

Hello Rami,

You're right, the datasheet could be more clear on the top of page 25 about this and I'll put a note in for this to be improved. Thanks.

The only indication I see is that figure 11, just below the above text does illustrate that CLKout0 which is the same frequency as distribution path (bypass) not going low during SYNC assert.

73,
Timothy

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lmk04033beval divider issues