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LMK03001: OSC input specification

Seng Puay Huin
Prodigy 20 points
Part Number: LMK03001

My OSC input to the LMK03001  is  connected  single ended  and AC coupled.  The datasheet shows the specification for the OSC input  is  between 0.2Vpp and 1.6Vpp.   Does  it means that  OSC input  of 0.2Vpp  to LMK03001 will function correctly?   The OSC input goes to R Divider  and then to the Phase Detector.   Can the Phase Detector  work correctly with such a low voltage of 0.2Vpp?  Is there a voltage range for OSC input for a particular setting. Example :  R15(PLL_CP_GAIN[1:0]) ?

  • 0
    TI__Mastermind 28540 points
    Hello Seng,

    The only factor for different OSCin is the register OSCIN_FREQ should be set appropriate to the OSCin frequency. Otherwise it does not matter the other LMK03001 settings given your OSCin signal.

    Note the spec of Vod = 0.2 V is for a differential signal. Technically units of Vod should be V, not Vpp. When an input has a Vod = 0.2 V, this means the Vpp voltage on each input pin is 0.2 V. When applying 0.2 Vpp on each OSCin pin, the total differential voltage swing would be 0.4 Vpp.

    73,
    Timothy
  • 0 in reply to Timothy T
    Prodigy 20 points

    Hello Timothy,

         From your explanation,  OSC input  of 0.2V  is referred to a single input voltage.  For single ended ended input ,  what is  the minimum and  maximum voltage that  osc input can have. 

    Below is the electrical characteristics of LMK03001

    Symbol                   Parameter                                                            Condition                                           Min  Typ     Max     Unit

    VOSCin square       Square Wave input Voltage for OSCin            AC coupled: Differential(Vod)                  0.2                1.6       Vpp

                                    and OSCin*

    Regards,

    Huin

  • 0 in reply to Seng Puay Huin
    TI__Mastermind 28540 points
    Hello,

    I would recommend between 0.4 and 2.4 Vpp SE. For low frequencies, keep slew rate above 0.15 V/ns. >= 0.5 V/ns recommended.

    73,
    Timothy