AWR2243: How to handle unused pins such as FMCW_CLKOUT, FMCW_SYNCOUT?

Hi 

Customer found mismatches regarding unused pins handling such as FMCW_CLKOUT, FMCW_SYNCOUT.

They are trying to design the 4-chips cascade design using AWR2243 following the reference design. and also would like to clarify how to handle the unused pins above.

The reference schematic added comments as "unused terminated to 50 ohm"  for the pins.

However the AWR2243 schematic guideline says to make unused pins floated in case of single chip design case.  This makes me confused. 

Could you please let me know how to handle unused pins of FMCW_CLKOUT and FMCW_SYNCOUT if customer designs 4-chip cascade way?

Please see the reference schematic below. it's shown from page 10~ with AWR side.

https://www.ti.com/lit/df/tidrzz2a/tidrzz2a.pdf?ts=1618243148442&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FAWR2243

• NOTE: AWR FMCW CLOOUT/SYNCOUT unused terminated to 50 ohm per datasheet requirement.

What's the exact meaning of the sentence above captured from reference schematic? I could not find the datasheet' requirement for this as well.

Also see AWR2243 Cascade (Rev.B) App Note. page 8

www.ti.com/.../swra574b.pdf

• LO Output Ports: There are two LO output ports. Either port can be used or both ports can be used. Unused LO output ports should be left floating at the BGA pad.

Please clarify about unused pin handling especially for FMCW_CLKOUT and FMCW_SYNCOUT in case 4-chips cascade design.

Thanks.

Regards, 

Jack