Hi, I want to use an external clock on my limesdr mini. After research I have two questions left:
First:
The LMK00105 states a maximal CLK-IN voltage of 2 Vpp. My ocxo has an 10MHz square wave output which swings between 0V and 3.3V. That said I should be able to connect my ocxo directly to the limesdr without attenuation. Is this correct?
Second:
After changing to an external reference clock the LimeSDR Mini doesn’t pass a certain calibration. Is the calibration in question the one of the VCTCXO ADC? So this doesn’t affect the tx or rx calibration in any way ? (I am asking because I learned that the limesdr transmits a constant carrier if the tx calibration fails which I want to avoid)
Regards
Hi @sigrokBlack,
Not sure, how did you connect external reference clock. Hence assuming you remove ed R59 and soldered R62, check schematic:
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CLKin voltage of LMK00105 is up to Vdd hence 3.3V is fine.
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If my assumption above is correct then VCTCXO DAC have no influence. You have to change reference clock frequency in LimeSuiteGUI in SXR/SXT/CGEN tabs to tell what your reference frequency is.
Hi, thanks for your help, that helped but it started a third question:
You have to change reference clock frequency in LimeSuiteGUI in SXR/SXT/CGEN tabs to tell what your reference frequency is.
So using LMS_SetClockFreq()
in a C program would have the same effect as setting the reference manually using LimeSuiteGUI?
Regards!