ADM3251 heat generation

Document created by analog-archivist Employee on Feb 23, 2016
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Interfaces using ADM3251E are working properly but it is noticeable hating of
the ADM3251E device. Question from customers:
- Is this a normal symptom?
- Maybe a bug in the application?


Yes, the ADM3251E can have a tendency to run a little hot. This is because it
uses 1st generation isoPower die which isn’t very efficient. The only thing you
can do really to improve things is to ensure the gnd pads are as large as
possible with multiple vias from each of the pads to the pcb ground plane. See
Figure 21 on page 13 of the ADM3251E datasheet for recommended layout.
We also have a dual channel version of this chip called the ADM3252E which
released this year. This uses more efficient isoPower die so won’t generate as
much heat. It can also operate from a 3.3V supply which improves efficiency
further. The theta-ja of the package will also be lower than the ADM3251E which
also helps reduce heat generation. It comes in a 44-pin BGA package and is more
expensive than the ADM3251E so might not be an option for the customer.