I need to add ethernet connectivity to a PIC18f66j60.

The datasheets tells about magnetics. But I know only very little about that.

Do you know any surface-mount magnetics suitable for this use ?

I look for external magnetics. MagJacks are not an option.


PIC18f ethernet magnetics schematics PIC18f ethernet magnetics requirements


I've found a lot of parts such as H1102 or H2019, but they feature a kind of coil beetwen the two output pins. Will that work ?

H1102 internals

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    \$\begingroup\$ This seems like a question that some simple Google searching would yield answers for. I found a hit on the first page of results. \$\endgroup\$ Jan 29, 2014 at 16:07

2 Answers 2


I have used the H2019 in the past. Here is a snippet of a schematic of it connected to a PIC and a RJ45 jack:


This additional transformer forms so called "common mode choke" - it protects against interferences induced on both wires of the twisted pair, but doesn't affect transmission of the useful signal which is transmitted as differential signal. So if other parameters (e.g. turns ratio, bandwidth) are correct, this additional transformer should only improve operation.


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