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LMK04803B / 2000MHz CLK out

Ryuji
Guru 20090 points


Hello,
 
I have the some questions about LMK04803B.
Please see the attached file.
 
According to the Webench Clocl tree buiilder and product folder information , we can use LMK04803B by 2000MHz of CLKout.
But in the datasheet P.17 , Maximum Freaquency(Min) is 1536MHz.
 
(1)
Can we use LMK04803B by 2000MHz clock out ?
 
(2)
Is 2000MHz clock out with LMK4803B guaranteed?
 
(3)
Are there any restriction for 2000MHz clock out?
 
Since our customer request this information urgently, please let me have by 3/Dec JPN time ?
Sorry for bothering you, but our customer already designed LMK04803B with 100MHz input and 2000MHz output , 250MHz output x 2...We must tell TI's opinion asap...
 
Best Regards,
Ryuji Asaka
 
 
  • 0
    TI__Mastermind 28560 points

    Ryuji Asaka said:
    (1)
    Can we use LMK04803B by 2000MHz clock out ?

    Yes.  I recommend using LVPECL or 2VPECL.

    Ryuji Asaka said:
    (2)
    Is 2000MHz clock out with LMK4803B guaranteed?

    What are you looking for with respect to guaranteed?  The amplitude level is not assured but the output will operate.  See the figure 5-1, 5-2, and 5-3 in the datasheet.  This shows expected behavior or the output amplitude as frequency increases.  As you can see, I recommend that LVPECL is used.

    Ryuji Asaka said:
    (3)
    Are there any restriction for 2000MHz clock out?

    It is not permissible to use analog delay feature above 1536 MHz.  Otherwise refer to the figures for output amplitude in datasheet.

    73,

    Timothy