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LMK5C33216A: LVPECL/LVCMOS RMS jitter

Kevin Huang67
Intellectual 370 points
Part Number: LMK5C33216A
Other Parts Discussed in Thread: LMK5B33216, LMK5C33216,

Hi sir,

In the datasheet, it only has the HSDS ouput RMS jitter value(12Khz~20Mhz).

What's the 3.3V LVPECL ouput RMS jitter value(12Khz~20Mhz) of 245.75MHz ?

What's the 3.3V LVCMOS single output RMS jitter value(12Khz~20Mhz) of 122.88MHz ?

  • 0
    TI__Genius 10875 points

    Hi Kevin,

    1. The LMK5B33216 does not provide traditional LVPECL outputs. Instead, the HSDS driver with programmable swing and common-mode voltage can be used to generate "AC-LVPECL" type outputs. Please refer to the HSDS jitter mentioned in the datasheet for LVEPCL outputs.
    2. Here is the phase noise plot (typical measurement from my bench) of OUT1 set to 122.88MHz, 2.65V LVCMOS. OUT0 and OUT1 support 1.8V and 2.65V LVCMOS output options.

    Regards,

    Jennifer

  • 0 in reply to Jennifer Bernal
    Intellectual 370 points

    Hi Jennifer,

    Yes, LMK5B33216 does not provide traditional LVPECL outputs.

    But LMK5C33216 provide traditional LVPECL outputs and RMS jitter typical 50fs(12khz~20Mhz) of 245.76MHz. Is it right ?

    Do yo know which clock generator has the smallest 3.3V LVCMOS single output RMS jitter value(12Khz~20Mhz) of 122.88MHz ?

  • 0 in reply to Kevin Huang67
    TI__Genius 10875 points

    Hi Kevin,

    1. Sorry I misspoke, the LMK5B33216 is similar to LMK5C33216A, which has improved jitter performance and is the latest silicon. LMK5C33216 (non-A) is the older model. All of these parts do not have traditional LVPECL as the swing and common-mode are programmable. We recommend using the LMK5C33216A for your application with 245.76MHz and 122.88MHz outputs.
    2. How many LVCMOS outputs do you need? You could generate a 122.88MHz HSDS output from the LMK5C33216A to get the best jitter performance then route it through a differential to single-ended buffer such as LMK00105 and LMK00804B.

    Regards,

    Jennifer