DRA80M: Do I need to connect all 3 external crystals?

Marcus Frech

Intellectual 1470 points

Part Number: DRA80M

Hi,

the way I read the data manual and TRM is, that it is enough to connect WKUP_OSC0 to operate DRA804M.

Is that correct?

It also looks like I can use this as input clock for the SERDES modules.

Is that correct and do I have disadvantages compared to usung serdes_refclock?

Many thanks and best regards

Marcus

over 6 years ago

0 Mariya Petkova over 6 years ago

TI__Expert 4885 points

Hi, Marcus Frech,

About WKUP_HFOSC0 - yes, only this oscillator can be connected to the device and it will be functional.

Also, the WKUP_HFOSC0_CLK can be used as input reference clock.

About the disadvantages of using WKUP_HFOSC0_CLK compared to external SERDES_REFCLOCK, I am not familiar. Will ask around and come back to you.

Regards,
Mariya

0 Marcus Frech over 6 years ago in reply to Mariya Petkova

TI__Intellectual 1470 points

Hi Mariya,

many thanks for the fast reply.
Looking forward to feedback on SERDES ref clk.

Cheers
Marcus

0 Mariya Petkova over 6 years ago in reply to Marcus Frech

TI__Expert 4885 points

Marcus Frech,

The disadvantage of using the internal clock may be the bigger jitter if a lot of modules are sourced by this clock.
Another advantage of using an external oscillator is that one can use oscillator with TCXO.

Regards,
Mariya

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DRA80M: Do I need to connect all 3 external crystals?