WHD72301G 10/100BASE-TX LAN Transformer

The WHD72301G holds ten 1CT:1CT units, split across five ports at two channels — one pairset — each.

The drawing groups them as TD1/RD1 through TD5/RD5, each pairing with a TX/RX group on the cable side to form one complete 100M port. Five ports in one device means a 65.70 mm body: the layout has to reserve that whole straight run, and routing between ports has to be planned in one go, unlike discrete single-port parts in the 10/100 BASE-T range that can be spread around the board.

Yes. The five groups inside the WHD72301G are independent, so unused ports can be left unconnected and the termination network built only for the ports actually in use.

The trade-off is clear: what is saved is part numbers and purchasing overhead, what is spent is board area — the device still occupies its full 65.70 mm regardless of how many ports are wired. Where only three ports are ever needed, a quad-port device or three single-port parts is usually the better buy; fitting a five-port part and wiring selectively makes sense mainly when models with different port counts share one board.

Outline, hole pattern, port count and internal unit count are identical; the element order differs — the WHD72301G puts the common-mode choke on the chip side, the WHD72302G on the cable side.

Both bodies are 65.70 × 6.50 mm and 12.00 mm Max high, on 1.78 mm pitch with a 58.74 mm span and 3.30 mm row spacing, and both hold ten 1CT:1CT units across five 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.