ADE7878 and paddle description discrepancy (SR#: 1237895)

Document created by analog-archivist Employee on Feb 23, 2016
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Discrepancy paddle connection wrt the datasheet and the eval-board.

In the datasheet of ADE7878 (rev.E) page 16 , Table 8 states not to connect the
Exposed pad to Analog ground (AGND). While the document of evaluation board
(UG-146 Rev.0) page 25 , according to figure 37 one must connect the exposed
pad to AGND!. Also the eval-board JP3 have the option to (connects the exposed
pad to AGND). The standard connection in the Eval board connects the Exposed
pad to AGND.

Waiting for your kind assistance,

 

The pad is not connected internally to the die, it is often use for thermal
relief. One can leave the pads to float (i.e. unconnected).
but...
Normally most IC Paddle (aka pad) would be tie to gnd... But on this occasion
due to EMC, ESD and EFT tests found that noise coupled into the die through
the pad. Therefore, the datasheet was modified as stated. Hence leave the pad
underneath unconnected, but solder the pad of ADE7878 by means of vias to
confer mechanical strength.

Pending on customers applications/conformance/compliance. In the eval-board
there is
a jumper option where you can connect and disconnect from gnd, where you can
test it out.

From my opinion the primary concern here is the coupling. and is not related to
the stability.

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