CDCE72010: skew

[FAE] Andrew Wang

Genius 10685 points

Part Number: CDCE72010

Hi Team,

Customer is using CDCE72010:

Output1: LVPECL, divide by 1

Output2: LVCOMS, divide by10

Customer wants to know how to determine the skew btw Output1 & Output2, thanks!

Andrew

over 3 years ago

0 Noel Fung over 3 years ago

TI__Guru* 81400 points

Hi Andrew,

All outputs are automatically phase aligned by the internal circuitry, see Figure 36 of the datasheet for details.

0 [FAE] Andrew Wang over 3 years ago in reply to Noel Fung

TI__Genius 10685 points

Hi Noel,

Customer wants to know amount of skew at their setup condition.

Are you saying, we can make 0ps skew for this device?

LVPECL

LVCMOS

Difference in btw:

Andrew

0 Noel Fung over 3 years ago in reply to [FAE] Andrew Wang

TI__Guru* 81400 points

Hi Andrew,

0 skew is impractical, unless you use the delay adjustment to manually reduce the skew. Since the divider value for both outputs are not identical, I expect the skew will be a few ns.

0 [FAE] Andrew Wang over 3 years ago in reply to [FAE] Andrew Wang

TI__Genius 10685 points

Hi Noel,

Sorry, I guess you probably mis-understand my question, I was asking for the how much skew btw Output1 vs Output2 would be if customer set config as below

Output1: LVPECL, divide by 1

Output2: LVCOMS, divide by 10

Since datasheet didn't specify it, so any rough number that would make sense should be ok to provide to customer, thanks for help!

Andrew

0 Noel Fung over 3 years ago in reply to [FAE] Andrew Wang

TI__Guru* 81400 points

Andrew,

As you can see from the table, if all the dividers have the same divide ratio, the skew is xxps. However, if the divide ratio are not the same, the skew goes up to >1ns. There is also a xxxps skew between CMOS and LVPECL. So my guess is a few ns in customer's configuration.

0 [FAE] Andrew Wang over 3 years ago in reply to Noel Fung

TI__Genius 10685 points

Hi Noel,

I have further question, let me take this offline discussion, thanks for helping out!

Andrew

Clock & timing

Clock & timing forum

CDCE72010: skew