PoE Splitter: What Is It and How Does It Work?

A PoE splitter separates the power and data carried together over a Power over Ethernet connection into two separate outputs. This allows certain devices that do not have a PoE-enabled Ethernet port to receive network data through Ethernet while getting power from a separate DC input.

PoE splitters can be useful when PoE infrastructure is already available but the device at the endpoint was not designed to accept power directly through Ethernet. Rather than running a separate electrical connection for the entire distance, power and data can travel together over the Ethernet cable and be separated near the device.

How Does a PoE Splitter Work?

A PoE splitter is installed at the powered-device end of an Ethernet connection. The incoming cable carries both power and network data from a PoE switch or another compatible power source.

Inside the splitter, the two functions are separated. Ethernet data is sent to a network output, while electrical power is converted to the voltage and connector required by the device. The device therefore receives two separate connections even though a single PoE cable was used to carry power and data to its location.

When Is a PoE Splitter Needed?

A PoE splitter is primarily useful when the network provides PoE but the endpoint is not natively PoE compatible. The device may have a standard Ethernet port for network connectivity along with a separate DC power input.

Instead of installing an electrical outlet near the endpoint, an appropriately selected splitter may allow the existing PoE connection to provide both requirements. This can be particularly useful when adding network-connected equipment in locations where conventional power is inconvenient or where PoE cabling is already installed.

The device must still be compatible with the splitter’s output voltage, connector and available power.

PoE Splitter vs. PoE Injector: What’s the Difference?

A PoE splitter and PoE injector perform opposite jobs. A PoE injector adds electrical power to an Ethernet connection. A PoE splitter takes a powered Ethernet connection and separates it back into individual power and data outputs.

An injector is generally located closer to the network switch when the switch itself does not provide the required PoE. A splitter is located at the other end of the connection, near a device that cannot accept PoE directly.

In some installations, an injector can add power at one end and a splitter can separate it at the other. However, when both the network switch and endpoint already support standards-based PoE directly, neither device is normally necessary.

How Do You Choose a PoE Splitter?

A splitter needs to match both the PoE source and the equipment being powered. One of the most important specifications is the splitter’s DC output voltage. A device designed for a particular input voltage must receive the correct voltage from the splitter.

Available wattage also matters. The splitter must support enough power for the connected device after accounting for its own conversion requirements and the power available through the PoE connection. Connector size and polarity should also be verified before connecting the equipment.

Because PoE can operate at several different power levels, the fact that a splitter physically connects to Ethernet does not mean it is appropriate for every PoE application. Our guide to PoE power levels explains how much power the different PoE types can provide.

Can a PoE Splitter Work With PoE++?

Splitters are available for different PoE standards, including equipment designed for higher-power connections. However, both the splitter and the power source must support the required standard and wattage.

Higher input power also does not mean the connected device automatically receives that same wattage or voltage. The splitter converts the incoming PoE power into an output appropriate for the endpoint, and its own specifications determine what it can deliver.

For a comparison of the major standards, see PoE, PoE+ and PoE++.

Does a PoE Splitter Extend Ethernet Distance?

No. A standard PoE splitter separates power and data but does not normally extend the Ethernet channel. The usual copper Ethernet distance limit still applies between the network equipment and endpoint.

If a device is located beyond the normal Ethernet channel length, the network architecture needs to address that distance separately. See our guide to PoE distance for a closer look at the 100-meter limit and ways longer connections can be designed.

Are PoE Splitters Used in Smart Buildings?

PoE splitters can provide a practical bridge between PoE infrastructure and network-connected equipment that was not originally designed for native PoE power. They can therefore be useful in retrofits or specialized applications where replacing an otherwise suitable device is unnecessary.

For larger intelligent-building deployments, however, equipment designed to accept PoE directly can simplify the infrastructure by eliminating additional conversion hardware at the endpoint. A splitter is best viewed as a solution for a specific device requirement rather than something every PoE connection needs.