LMK05318: LMK05318 application question

Part Number: LMK05318

Tool/software:

Hi team,

our customer meet below question:

The LMk05318's PRIREF input clock is the LVDS reference clock extracted by the Mac chip. Why do I need to select the CMOS Slew Detector in the SET Refererence Validation settings? Why can't I use the Amplitude Detector? As I understand it, it's more reasonable to detect the amplitude of a differential signal.

in datasheet, we recommend use CMOS detector mode under 5M frequency even for differential signal. and in their real application, they found they can only use the CMOS mode with 40M frequency.