I want to use the AD7606-4 in PARALLEL BYTE mode as described on page 27 of the datasheet Revision A under CONVERSION CONTROL section.
pin 33(DB15/BYTESEL) and
pin 34(REF SELECT) pulled HI.
pin 30(DB12) and
pin 31(DB13) are tied to AGND.
My question is this: What should I do with pin 25(DB8/DoutB)?
First option "Leave it floating in the breeze." (Not a great design practice)
Second option "Also tie it to AGND with the other unused DB pins" (In my mind this makes sense for unused pins like DB9-DB13)
Third option "Terminate with a resistor to AGND or VCC". (This would seem reasonable if there is something going on on the pin that Analog Devices is not letting us know about in the datasheet)
There is no guidance in the manual, and phone support did not seem to pan out either. HELP!