Q1. On the ADXL327 datasheet there are six pins described as NC (No Connect).
Two of these pins (pins 1 & 9) are listed as "No Connect (or Optionally
Ground)". The remaining four pins (pins 4, 11, 13 & 16) are listed as "No
Connect" only. Must these be absolutely not connected?
We are experiencing short circuits under some of these devices, due to an
incorrectly specified land pattern.
We are able to detect some shorts, as the 'connected' signals are brought out
to test points.
However, as the NCs are not meant to be connected (and are therefore not
tracked), it is not possible to access these pins.
Would the device fail to function if any of the NC pins were shorted to
2. I’m curious, if they are not connected, why do two of them (and not the
others) state "or optionally ground"?
A1. As ADXL327 is the derivative from ADXL335 (NC pins are not internally
connected), so it should be OK to short NC pins to the adjacent pins. After
checking the bond diagram I can confirm that these pins are not connected to
anything internally, it shouldn't matter what they are connected to externally.
2. Pins 1 and 9 are connected to factory test pins, so you have the option to
ground those. The other four pins you mentioned should say "Not internally
connected" rather than "No Connect".