WHDG88403G Gigabit LAN Transformer

Land pattern, the grouping of all 88 pins and the electrical ratings are identical; the only difference is which side carries the common-mode choke — on the WHDG88403G it sits toward the high-numbered pins, on the WHDG88409G toward the low-numbered ones.

The mechanical sheets match value for value, including the 29.00 × 26.50 mm body, the 2.50 mm lead length and the same PCB mounting-hole drawing, so a change needs no board work but does need EMC re-measured.

Start from the area shape and the clearance the PCB can give — the three outlines do not interchange.

The WHDG88403G is a 29.00 × 26.50 mm block; the two 72-pin families are a 34.50 × 19.00 mm block and a 65.70 × 6.50 mm bar. Pads on the WHDG88403G are laid out on three different spacings, and the datasheet supplies a separate PCB mounting-hole drawing that has to be followed rather than the even rows used on the 72-pin parts.

The WHDG88403G body is 14.50 mm Max, plus up to 1.00 mm of standoff, making it the tallest of the four-port parts in this family.

The 72-pin block is 13.50 mm Max and the 72-pin bar 12.00 mm Max. Where internal clearance is tight, this belongs in the first round of selection rather than after the layout is done. Lower-profile options are listed in the 100/1000 BASE-T range.