WHSG24701D1 Gigabit LAN Transformer

No. The 5000 VAC figure on the WHSG24701D1 is an isolation withstand test condition, not a continuous working voltage. The datasheet states it in full as 5000 VAC at 1 mA for 2 s, describing the part's ability to survive that voltage for that duration without breakdown – a production verification condition.

The voltage a design may apply continuously across the barrier is far lower and is set by the system's insulation class and safety requirements, and the figure is not a system-level safety conclusion, which has to be assessed separately against the target standard. Among the parts in this batch only this one reaches that level; the others are rated 1500 VAC.

Allocate 350 mA per magnetic channel; do not read it as a port total, and do not multiply it by the channel count to reach a larger figure. The WHSG24701D1 datasheet places 350 mA on the same line as PoE Support IEEE802.3af 15W, indicating the current capability is dimensioned for an 802.3af port.

On the board, size all four centre-tap paths evenly against 350 mA, calculating copper width from your actual copper thickness and permitted temperature rise. What the PSE delivers and the PD draws is set by system classification and power management; the magnetics current capability is one constraint within that.

When isolation margin is the leading requirement and power delivery only needs to reach 802.3af 15W. Typical directions are industrial remote I/O, PoE camera interfaces, and Ethernet ports between a field side and a control side where extra insulation margin matters – designs of that kind are usually not short of power but short of common-mode surge and insulation headroom.

If the project needs higher PoE power rather than higher isolation, look instead at parts specified for 4PPoE in the 10/100/1000 BASE-T range; the current capability of the WHSG24701D1 is dimensioned for 802.3af. System insulation and safety conclusions still have to be assessed against the target standard.