The difference between Power over Ethernet (PoE) and Power over Data Lines (PoDL)

22.06.2023 | Both, PoE and PoDL can power Ethernet devices over data cable. However, the two are not compatible at all.

For many years Power over Ethernet (PoE) has been proving its worth in powering devices in Ethernet networks. For data rates up to 100 Mbps, Ethernet uses two twisted pairs, for higher data rates four pairs are needed. The new Single Pair Ethernet (PoE) uses just one pair for any data rate.

SPE, too, allows powering devices remotely via horizontal cabling, so no additional connector for power is needed. This is particularly beneficial when it comes to small components like sensors and actuators. The underlying technology is related to the well-known Power over Ethernet (PoE) but not compatible. Power over Ethernet needs a minimum of two wire pairs for powering devices, one pair in which the electrical current runs to the devices and another pair as a return path. Because of this, Power over Ethernet cannot be used for Single Pair Ethernet (SPE) which uses over just one wire pair to connect devices to the network.

To avoid any possible confusion with Power over Ethernet, a new name was created: Power over Data Lines (PoDL). PoDL is specified by IEEE 802.3bu. In standard operation devices can be powered typically with up to 50 W with an electrical current of up to 1360 mA.

Please note: PoE and PoDL are not compatible. With PoE the electrical current runs in one pair to the device and back in another pair, with PoDL it runs in just one wire in each direction.

Author:

Dirk Traeger

Technical Solutions Manager DataVoice