WHD16506G 10/100BASE-TX LAN Transformer

Same body, narrower hole span: both are 20.30 × 9.80 mm and 6.80 mm high, but the lead span on the WHD16506G is 15.24 mm against 17.78 mm on the WHD16503G, one 2.54 mm grid step shorter.

What is saved is hole span, not board area — the body has not shrunk and the clearance needed above it is unchanged. The practical effect is on routing: each row occupies one grid position less, freeing a little space at the ends.

Two 1CT:1CT units, forming the two channels — one pairset — of a single 100M port.

A 100M link uses only two differential pairs, one transmitting and one receiving, so two units suffice. The WHD16506G is a single-port part, one device per RJ45. Where two 100M ports are needed, either two single-port parts or one 20-pin dual-port part will do; the latter holds four units, one pairset to each port.

No. The WHD16506G is a non-PoE part: its centre taps serve only as AC termination and common-mode reference and carry no DC supply current.

A port that has to deliver power over the cable needs a part whose datasheet states a current capability, chosen at selection time — preferably one that names the scope as well, giving both a per-channel and a full-channel figure. PoE-rated parts are grouped in the Gigabit range.