This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LMK04XXX single input

Other Parts Discussed in Thread: LMK04100, LMK04133

Hi,all

Let me ask you a question about LMK04XXX.

・According to datasheet P1 , LMK04XXX  acccepts a differential input , however is it able to accept single input ?

・I think that LMK04XXX can operate with external VCXO or crystal , however what's purpose with them ?

 We wil use LMK04XXX for only removing input CLK Jitter.In the case , I think that an internal VCO can achieve without external VCXO or crystal .

Best regards.

Taichi

 

  • TheLMK04xxx can support single ended and differential inputs. For PLL1, it can operate with external VCXO or external pullable crystal with using external varactors to tune the crystal.

    Depending on which band of your input clock has jitter, the internal VCO can be good enough. If the noise is at high frequency (over 100kHz), the internal VCO would be fine. If the noise is at low frequency (less than 10kHz), it is better to use cascaded loop in LMK04xxx.

  • Hi Madhu

    Thank you for quick reply.

    Let me ask you an additional question.

    My customer will use single input for LMK04100 Family , however is following diagram on LMK04186 datasheet P108 able to adapt to LMK04100 Family ?

    Best regards.

    Taichi

  • Hi Madhu

    Thank you for reply.

    Additionally , let me ask you a question about LMK04133.

    In the case of using a fixed VCXO , could it output multiple frequency wave ?

    Once I use clock design tool , the result was following .

    LMK04133 with 100MHz(input,output) : VCXO = 250MHz , VCO = 2GHz

    LMK04133 with 200MHz(input,output) : VCXO = 200MHz , VCO = 2GHz

    In this case of need 100MHz and 200MHz , I think that LMK04133 needs 250MHz VCXO and 200MHz VCXO , however correct ? If possible , please teach me a solution to manage with the only VCXO .

    Best regards.

    Taichi.

     

  • Hi , all

    Let me ask you a question about LMK041XX.

    ・Output frequency is written on datasheet P3 table , however how it calculated from OSCin , VCO Divider , PLL2N , VCO frequency and output divider ? And this table is case of no external VCXO or crystal ?

    ・How much is RMSJitter in the case of using only PLL2 without external crystal or VCXO ?

    Best regards.

    Taichi