ADC12DJ5200RF: Phase Calibration issue

Ryker She

Part Number: ADC12DJ5200RF

Tool/software:

Hi expert,

My customer used two ADC12DJ5200 for phase calibration. Keep the first ADC12DJ5200 phase unchanged (32000 in phase control word). Then adjust the control word of the second ADC12DJ5200 and move toward the first phase. The phase difference between two ADC12DJ5200 was eventually calibrated to 0.02 ps. However, after 30 seconds of operation, the phase difference between the two ADC12DJ5200 increases to 1.9 ps (there was no operation running during this time). After the second calibration, the two ADC12DJ5200 phase difference can settle to within 0.5 ps. What could be the cause of this problem?

Besides, could you provide the details or applications of the ADC offset calibration correction, specifically background calibration (the datasheet only shows a little bit about how to do this, but do not go into detail on how to configure the registers at each step).

Best Regards,

Ryker

4 months ago

0 Eric Kleckner 4 months ago

TI__Expert 6150 points

Hello Ryker,

This could be caused by temperature change, if they are first calibrating the phase doing bringup of the ADC the adc will not have thermally soaked yet as it will be heating up. Then when they try and test the phase calibration later they will see it has changed just do the part and the board warming up.

Thanks,

Eric

0 Ryker She 4 months ago in reply to Eric Kleckner

TI__Expert 4430 points

Hi Eric,

Do we have some test result which can indicate the relationship between temperature change and phase change? Thanks.

Best Regards,

Ryker

0 Eric Kleckner 4 months ago in reply to Ryker She

TI__Expert 6150 points

Hello Ryker,

I will reply to this offline.

Thanks,

Eric

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ADC12DJ5200RF: Phase Calibration issue