LMK04616: Ref to Out phase variation, alternative device?

Nicholas Carley

Part Number: LMK04616
Other Parts Discussed in Thread: LMK04832

Hello,

We have found a major source of phase variation in our system, which is that the "REF-to-out" phase of the PLL that we use to lock to the 250 MHz distributed from the LMK04616 to produce the 6 GHz sampling clock for our RF DAC is not specified, and in fact has a severe (>5 ps/deg C) temperature dependence.

Can you recommend any PLLs that have good REF-to-out phase stability, especially over temperature?

Thanks,
Nick

over 4 years ago

0 Hao Z over 4 years ago

TI__Mastermind 18070 points

Hello,

This ticket has been assigned and we'll get back to you soon.

Regards,

Hao

0 Nicholas Carley over 4 years ago in reply to Hao Z

TI__Expert 8495 points

Hello Hao,

I wanted to check in on this, any updates?

Thanks,
Nick

0 Derek Payne over 4 years ago in reply to Nicholas Carley

TI__Mastermind 29830 points

Hi Nick,

First, are you using the LMK04616 in zero-delay mode? Zero-delay mode routes the output divider back as the feedback, allowing for a much smaller variation in delay between reference and output.

If zero-delay mode on the LMK04616 is still insufficient to get the desired performance, I recommend using the LMK04832 in zero-delay mode instead.

Regards,

Clock & timing

Clock & timing forum

LMK04616: Ref to Out phase variation, alternative device?