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LMX2492: Fin and OSCin pins frequency limits? Frequency sweep on OSCin?

Part Number: LMX2492


Can you please help with the below questions?

  1. The lower frequency limit of the Fin pin is 500 MHz according to the data sheet.
    Is this a hard limit? Does the input still work below 500 MHz? Or is it just not specified for frequencies below 500 MHz?
    Will it probably work down to 100 MHz or even lower or are there any technological reasons that prevent this?

  2. Same question for the pin f_OSC_in: The lower limit is 10 MHz according to the data sheet.
    Does the device still work at lower frequencies?

  3. We would like to perform a frequency sweep (with a DDS) on f_OSC_in, while operating the device in integer mode.
    We hope to achieve a better spur performance by sweeping f_OSC_in instead of using the internal sweep generator.
    Is this possible?
    Are there any technological reasons that prevent sweeping the reference frequency f_OSC_in?

Thanks in advance,


  • Hi AnBer,

    These frequency specifications are not hard limit, it may work beyond the spec. However, during characterization, we found some samples will not function properly beyond these limits so in our factory, we will test each device at these frequencies to ensure every device meets datasheet specification. In other words, you can operate the device beyond the specifications but the performance is not guaranteed. 

    Yes, you can sweep the reference clock instead of the N-divider.