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ADC3649: SYSREF Interface Between LMK04832 and ADC3849

Part Number: ADC3649
Other Parts Discussed in Thread: LMK04832, LMK04828

Hello E2E Experts,

I need to synchronize multiple ADC devices vis-a-vis the SYSREF/GPIO0 pin of the ADC3649 using the CLKOut drivers of an LMK04832 IC.  SInce the GPIO0 is a single-ended input with a 1.8V expected level (maximum input is DVDD18 + 0.2), this is a problem as the LVCMOS level from the CLKOut ports of the LMK chip are 3.3V - 0.1.  Without using a level transaltor for each CLKOut used as a SYSREF, is there an easier way to do this?  Section 9.2.2.2 of the ADC3649 says: In multi-channel systems the SYSREF signal can be generated using a LMK04828 or LMK04832 device.  What interface circuit was intended here?

Could I use a LVCEPL mode for the CLKOuts used as SYSREF and wire it in a way to meet the single-ended requirements for the ADC3649's GPIO0 voltage ratings/thresholds?

 

 

What do you recommend here.