LMK05028: Can I use LMK05028 as PTP Boundary Clock?

KAEDE KUDO

Part Number: LMK05028
Other Parts Discussed in Thread: LMK05318

Hello,

I have a question about LMK05028.

I confirmed the following statement in D/S.

• SyncE (G.8262), SONET/SDH (Stratum 3/3E,
G.813, GR-1244, GR-253), IEEE 1588 PTP Slave
Clock, or Optical Transport Network (G.709)

Can I use LMK05028 as PTP Boundary Clock?

Best Regards,

Kaede Kudo

over 6 years ago

0 Timothy T over 6 years ago

TI__Mastermind 28550 points

Hello Kudo-san,

Yes, the LMK05028 can be used as a boundary clock.

73,
Timothy

0 KAEDE KUDO over 6 years ago in reply to Timothy T

Expert 2700 points

Hello Timothy-san,

Thank you for your fast reply!

I understood it.

Can I use LMK05318 as a PTP boundary clock as well?

Best Regards,

Kaede Kudo

0 Timothy T over 6 years ago in reply to KAEDE KUDO

TI__Mastermind 28550 points

Hello Kudo-san,

My understanding is no because it doesn't have the two DPLLs. LMK05318 has 1 DPLL and 1 APLL.

73,
Timothy

0 Brent Gao over 6 years ago in reply to Timothy T

TI__Prodigy 180 points

Hi Timothy, the LMK05028 has two DPLL and LMK05318 has one DPLL. just a little confuse your answer. thanks.

0 Timothy T over 6 years ago in reply to Brent Gao

TI__Mastermind 28550 points

Hello Brent,

LMK05028 can function as PTP boundary clock because it has 2x DPLL.

LMK05318 cannot function as PTP boundary clock because it has 1x DPLL.

73,
Timothy

0 KAEDE KUDO over 6 years ago in reply to Timothy T

Expert 2700 points

Hello Timothy-san,

Thank you for your reply.

I understood your comment.
I was wondering how to distinguish and introduce the LMK05028 and LMK05318 to the customers, so it was very helpful.

I am sorry for my lack of study, but please let me know one more point.
How is the PLL configuration related to the PTP boundary clock?

Best Regards,

Kaede Kudo

0 KAEDE KUDO over 6 years ago in reply to KAEDE KUDO

Expert 2700 points

Hello Brent-san,

Thank you for your support!

Best Regards,

Kaede Kudo

0 Madhu Balasubramanian over 6 years ago in reply to KAEDE KUDO

TI__Expert 4400 points

Kudo-san,

Are you referring to just the PTP boundary clock as defined in IEEE1588-2008 or a telecom boundary clock with additional performance specifications given in G.8273.2 T-BC and other related standards for PTP and SyncE. What is the data rate for the physical layer? Please get this confirmation.

The boundary clock implements a local PTP clock which can be synchronized to a master on an upstream node and act as a master to the downstream nodes. In a boundary clock implementation, the time and frequency synchronization must be guaranteed on the local PTP clocks on each node. For telecom boundary clock, Synchronous Ethernet implements frequency synchronization via the physical layer and PTP handles time synchronization. In just the PTP boundary clock implementation, PTP handles both time and frequency synchronization.

0 KAEDE KUDO over 6 years ago in reply to Madhu Balasubramanian

Expert 2700 points

Hello Madhu-san,

Thank you for your reply!
And I'm sorry for my late reply.]

I think that thanks to your answers, my understanding of PTP Boundary Clock has been deepened.
However, the customer's inquiry as PTP Boundary Clock is not an excuse.
I am sorry for the confusion.

What I wanted to know is why LMK05028 with two DPLLs can be used as PTP Boundary Clock and LMK05318 with only one DPLL can not be used as PTP Boundary Clock.
Could anyone clear me of my question?

Best Regards,

Kaede Kudo

0 Timothy T over 6 years ago in reply to KAEDE KUDO

TI__Mastermind 28550 points

Hello Kudo-san,

My understanding is that in the boundary clock, we need to have a high pass filter response to eliminate impact of the frequency switch. By using the two DPLLs together we can achieve this.

73,
Timothy

0 KAEDE KUDO over 6 years ago in reply to Timothy T

Expert 2700 points

Hello Timothy-san,

Thank you for your fast answer!

OK, I understood.

I will think a little more myself.

Thank you for your cooperation!

Best Regards,

Kaede Kudo

Clock & timing

Clock & timing forum

LMK05028: Can I use LMK05028 as PTP Boundary Clock?