AD9858_unused input pins connection

Document created by analog-archivist Employee on Feb 23, 2016
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I need your assistance with my DDS board, I have a DDS board with AD9858 chip,
and I'm only going to use the AD9858 chip with some pin's, but I don't know how
to connect the rest unused Pins? can you please assist me how to connect the
unused pins..? the unused pins numbers are:
  45 & 46 & 53 & 54 & 55 & 56 & 57 & 58 & 64 & 65 & 66 & 71 & 72 & 100

 

Pins 45, 46, 53, 54: Leave floating
Pins 55, 56: Leave floating.
Pin 57: 10k ohm pull-down to ground.
Pin 58: Bypass to GND with 0.1 uF cap.
Pin 64: 10k ohm pull-down to ground.
Pin 65, 66: Bypass to GND with 0.1 uF cap.
Pin 71: 10k ohm pull-down to ground.
Pin 72: Bypass to GND with 0.1 uF cap.
Pin 100: Leave floating.
It may be fine to leave Pins 57, 58, 64, 65, 71, 72 floating. The 10k pull-down
is a precaution to keep the input buffer from chattering. You should feel free
to experiment with no components on these pins, and if they suspect a noise
issue, install the components listed above.

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