WHD20701G 10/100BASE-TX LAN Transformer

No — three hole patterns exist here. One is 2.54 mm pitch with 7.62 mm row spacing and a 22.86 mm span; one is 2.00 mm pitch with 7.62 mm row spacing and an 18.00 mm span, which is where the WHD20701G sits; and a third uses 2.00 mm pitch but opens the row spacing to 10.16 mm.

The Pitch field on the 10/100 BASE-T range pages carries only 2.0mm and 2.54mm, so the second and third patterns look identical in the spec table while their row spacing differs by 2.54 mm and the holes do not line up at all. Selection has to come down to row spacing and span on the drawing.

Outline, hole pattern and internal unit count are identical; the element order differs — the WHD20701G puts the common-mode choke on the chip side, the WHD20702G on the cable side.

Both are 21.20 × 10.00 mm and 7.20 mm Max high, on 2.00 mm pitch with an 18.00 mm span and 7.62 mm row spacing, and both hold four 1CT:1CT units split between two ports. The footprint being the same, changing between them needs no PCB work; but the common-mode path has changed, so EMC has to be re-verified on the finished unit.

A 100M part, and the internal structure settles it: the WHD20701G holds four 1CT:1CT units split between two ports, two channels — one pairset — to each. That is two 100M ports.

A dual-port Gigabit device uses all four pairs per port, four channels each and eight units in total, twice as many. The product listing also classifies it under 10/100 BASE-T. Where a title block disagrees with the actual rate, go by the internal unit count and the product classification.