High power PoE and HDBaseT

Power over Ethernet (PoE) offers convenience, flexibility, and enhanced management capabilities by enabling power to be delivered over the same CAT5 cabling as data. This technology is especially useful for powering IP telephones, wireless LAN access points, cameras with pan tilt and zoom (PTZ), remote Ethernet switches, embedded computers, thin clients and LCDs.

The original IEEE 802.3af-2003 PoE standard provides up to 15.4 W of DC power (minimum 44 V DC and 350 mA) supplied to each device. The IEEE standard for PoE requires Category 5 cable or higher (can operate with category 3 cable for low power levels).

The updated IEEE 802.3at-2009 PoE standard also known as PoE+ or PoE plus, provides up to 25.5 W of power.

Although 2009 standard prohibits a powered device from using all four pairs for power, some vendors have announced products that claim to be compatible with the 802.3at standard and offer up to 51 W of power over a single cable by utilizing all four pairs in the Category 5 cable. The trend for power demands seem to be up.

Compliance to Power-over-Ethernet safety standards is critical when moving beyond 60W (EE Times)and Compliance with POE safety standards is critical when moving beyond 60W (EDN) articles tells that the current generation of standards-based technology enables up to 60 watts of power to be delivered over four pairs of cabling, which also improves efficiency when compared to earlier two-pair solutions. Compliance with POE safety standards is critical when moving beyond 60W.

As the industry moves toward delivering even more power over the CAT5-or-better cabling infrastructure, system designers and network administrators alike, need to understand various emerging technology options. Some new options can bring expensive and cumbersome deployment complications and, potentially, safety risks.

Some manufacturers have touted their own 100W-per-port solutions or even 200W/port solutions that are not safe. The use of a standard Ethernet-cabling infrastructure for a single port delivering greater than 100W is simply not safe under the NEC standard. The only safe approach for powering devices over Ethernet cabling is to follow IEEE802.3at-2009 specifications. Moving beyond the LPS requirement (sub-100W/port LPS requirement of IEC 60950-1:2011) to greater-than-100W/port implementations requires that the cables be protected with special flame-resistant conduit. A metal enclosure is required if the total PD load is greater than 100W for information data equipment, or greater than 15W for TV and audio equipment.

One standardized 100W solution is one used by HDBaseT Alliance. HDBaseT Alliance is develops 100W power specifications for products that transport uncompressed, high-bandwidth multimedia content, 100BaseT Ethernet, power, and various control signals through a single LAN cable. The key differences between the HDBaseT-powering approach and those from other independent manufacturers pursuing higher power levels are that it:

  • Complies with the section 33.7.1 of the IEEE802.3at-2009 standard, which mandates that all PSEs conform to International Electrotechnical Commission (IEC) 60950-1:2001 specifications including classification as a Limited Power Source (LPS) carrying no more than 100 volt-ampere (VA) – or 100W – per port without the need for special over-current protection devices, and
  • Performs Powered Device (PD) detection followed by PD classification to determine a PD’s consumed power level prior to its ignition.

In a typical HDBaseT implementation, the PSE is installed and powered by a 50 to 57-volt DC power supply, and all PDs receive power directly over the HDBaseT link across all four pairs of CAT5-or-better cables. Additionally, core PoE technology has been enhanced for HDBaseT to use a 1 amp current for every two cabling pairs, 3-event classification to identify compliant PSEs, and identify the cable length/resistance (draw more power when required not exceeding 100W, rather than assuming a worst-case cabling infrastructure at all times). This enables HDBaseT technology to transfer of up to 100W of continuous DC power, per port, from one side of the HDBaseT link to the other.

HDBaseT is fully backwards-compatible with the IEEE802.3at-2009 PoE specification. HDBaseT also does not infringe on any of the mandated PoE safety requirements.

HDBaseT’s ability to deliver up to 100W of power (over 100m, via a single LAN cable, without any additional power source) is actually very nicely aligned with trends in energy usage and demand. The power level is more than adequate for supporting today’s typical 40-inch LED TV, which requires 70W of power. It is expected that both LCD and LED TV monitors will soon be averaging approximately one watt of power consumption per inch of screen size. Regardless of screen size EnergyStar™ 6.0 is targeting a cap of 85 W for all screen sizes.

PoE continues to evolve and offer an even wider variety of high-value power-delivery and management capabilities.


  1. Tomi Engdahl says:

    The Ethernet Alliance notes its PoE Certification program “is crucial to minimizing interoperability issues and fueling a positive user experience with IEEE 802.3 standards-based PoE.”

    The consortium adds:
    With IEEE standards defining more efficient and robust methods of delivering electrical power along with data from power sourcing equipment (PSE) such as Ethernet switches to powered devices (PDs) via Ethernet cabling, the world is amid sharp growth in the number and variety of PoE-powered devices, including wireless access points, phones, cameras, speakers, LED lighting and many others.
    Dell’Oro Group predicts nearly 780 million Ethernet switch PoE ports will ship from 2021 to 2025. Based on a test plan developed by many of the same individuals who helped write the IEEE 802.3 PoE standards, the Ethernet Alliance PoE Certification program enables simple and clear identification of those PSE and PD products that will successfully work together and dependably deliver the differentiating power and efficiency benefits promised by IEEE-standardized PoE.

    “Approving UL as an additional third-party testing lab expands the worldwide coverage of the Ethernet Alliance PoE Certification program,”


  2. Tomi Engdahl says:

    Remee says 21 AWG twisted-pair cable is 100Ω, RJ45-compatible

    Remee claims its proprietary “utility Twisted Pair (uTP)” technology results in a twisted-pair power cable that allows for data and power to run over longer distances than traditional twisted-pair cable.

    As part of its Activate by Remee Powered Cable Solutions product line, Remee Wire & Cable (Florida, NY) has announced the launch of its new family of 21 AWG utility Twisted Pair (uTP) cables. The manufacturer claims its proprietary uTP technology results in a twisted-pair power cable that allows for data and power to run over longer distances than traditional twisted-pair cable.

    According to the company, “truly a utility cable, the new Activate by Remee uTP cable is 100Ω, RJ45 -compatible and can be used for network appliances that require data and power to be delivered to locations that fall outside of the traditional Ethernet ring topology.”

    Remee claims that the new cable’s capabilities encompass more potential applications than PoE or powered cables may provide, including those for:

    PoE Lighting
    PoE Type 1, 2, 3 and 4 devices in the IoT
    Industrial factory floors

    In conjunction with its new uTP product launch, Remee has introduced its Activate by Remee Bandwidth / Power Optimization Chart, a useful table that factors in the bandwidth and speed requirements of the new data cable, along with the power requirements of the cable run, considering VDC, amps, and wattage.

    Based on these inputs, the chart reveals the appropriate power distance (in feet) of various copper gauge sizes. The table also covers the optimized uTP cables to illustrate the distance capabilities for PoE (802.3af), PoE+ (802.3at), PoE++ (802.3bt Type 3), and PoE++ (802.3bt Type 4) where Activate by Remee cable is selected.

    The table is billed as a tool to help cabling installers, contractors, integrators and end users determine: the distance possible for IEEE 802.3 PoE


  3. Tomi Engdahl says:

    Waveshare PoE HAT for Raspberry Pi

    This is the PoE HAT which is designed for Raspberry Pi.
    A 0.91inch OLED is embedded for information displaying.
    Cooling fan is added for cooling.
    Supports 802.3af PoE.

  4. Tomi Engdahl says:

    #365​ Is Power over Ethernet (POE) on the ESP32 any good? (New TTGO and Olimex boards available)

    How should we connect devices to our home network? Wireless or wired via Ethernet? Do these new POE boards from TTGO and Olimex change anything? Interesting questions. Let’s have a closer look.
    We all know: Wireless IOT devices are cool. But they have some drawbacks. This is why we want to look at the alternative: Wired IOT devices

  5. Tomi Engdahl says:

    FUN; you don’t need water cooling for high power Ethernet cable

    I hate when the internet starts to leak again

  6. Tomi Engdahl says:

    Developing A Power Over Ethernet Stack Light

    A common sight on factory floors, stack lights are used to indicate the status of machinery to anyone within visual range. But hackers have found out you can pick them up fairly cheap online, so we’ve started to see them used as indicators in slightly more mundane situations than they were originally intended for. [Tyler Ward] recently decided he wanted his build own network controlled stack light, and thought it would double as a great opportunity to dive into the world of Power Over Ethernet (PoE).

    Now the easy way to do this would be to take the Raspberry Pi, attach the official PoE Hat to it, and toss it into a nice enclosure. Write some code that toggles the GPIO pins attached to the LEDs in the stack light, and call it a day. Would be done in an afternoon and you could be showing it off on Reddit by dinner time. But that’s not exactly what [Tyler] had in mind.

    He decided to take the scenic route and designed his own custom PCB that combines an Ethernet interface, PoE hardware, and the ESP32 into one compact unit. It’s no great secret that it only takes a few extra components to plug the ESP32 into the network rather than relying on WiFi, but it’s still not something we see done very often by hobbyists.

    POE stack light
    A POE powered lighting controller supporting both Artnet and HTTP control.

  7. Tomi Engdahl says:

    Protecting Power Over Ethernet (PoE / PoE++) Communications

    PoE is a transmission technology that passes power along with data on Ethernet cabling. A single cable provides power and data to devices such as voice over internet protocol (VOIP) telephones, security cameras using internet protocol, wireless access points, data center network routers, and industrial control systems. The IEEE standard for PoE is 802.3 and has been evolving since 2003 to enable the use of higher power.

    The 2018 evolution of the standard, 802.3bt, commonly referred to as PoE++, allows a maximum power of 90 W and as much as 960 mA of current on the data lines. Furthermore, this standard allows Ethernet transmission rates that can reach 10 Gbps, 10GBASE-T. However, the inclusion of power with low voltage digital signals requires that PoE circuits be protected from current overloads and voltage transients such as lightning, ESD, and other fast transients that propagate on an AC power line.

    Protecting a PoE++ Port

    Figure 1 illustrates an example PoE++ design and includes recommended protection components for current overload protection and transient voltage protection. The circuitry between the RJ45 connector and the protection network is designed to protect both the Ethernet Physical Layer (PHY) circuitry and the powered device (PD) controller.

    A fuse is recommended to protect each of the eight data lines from current overloads. Consider a slow blow fuse to avoid nuisance shutdowns from current surges due to a switching power supply or lightning surges. Another condition that the fuse can help avoid is damage due to an incorrectly wired or shorted power line. Ensure that the fuse you select is compliant with standards such as IEC 62368-1, Telcordia GR-1089, and FCC 47 Part 8 Surge Specifications. Fuses that meet these requirements have working current ratings of about 2A or less.

    Look for a fuse with an interrupting rating of as much as 100 A so that the fuse can open and not vaporize even under the worst-case overload condition. Fuses that meet the referenced standards can open in approximately a second to a 250 % overload. To enable the efficient assembly of the PCB, select a surface mount version that is suitable for reflow soldering.

    On the center tap of the isolating signal transformers, use a protection thyristor connected to earth ground to absorb and prevent voltage transients, including lightning strikes, from passing through the signal transformers. Protection thyristors, like Littelfuse SIDACtors®, are crowbar-type devices with low on-state voltage and the capacity to absorb high currents from transients.

    A fuse combined with a protection thyristor complies with global regulatory standards, GR 1080 and IEC 62368-1, for protecting telecommunications equipment.

    Protecting the Ethernet Physical Layer Chipset

    For the Ethernet PHY chipset, the major transients that can cause damage are ESD strikes, cable discharge events, and electrical fast transients on the data lines. A transient voltage suppressor (TVS) diode array can provide the necessary protection. To protect all eight data lines, use two 4-channel TVS diode arrays as shown in Figure 2.

    Protecting a PoE Network in a Building

    An intra-building PoE network is a less harsh environment; and, the PoE network only carries a maximum of 15.4 W or 350 mA. Here, protecting the PHY against harmful ESD events with a 2-channel TVS diode array is recommended.

    Protecting a PoE Network in an Outdoor Environment

    The outdoors is a much more severe environment for electronics than indoors. There is a higher risk for power-cross to cause over-current faults and also a higher risk of lightning-induced surges events. Like the PoE++ protection circuit, a time-delay fuse is recommended on each I/O line for any outdoor and harsh environment PoE circuits to protect against power-cross events.

    A gas discharge tube provides crowbar protection from lightning or other hazardous transients.

    Note that the fuse and gas discharge tube combination should meet all the regulatory requirements as described for the PoE++ standard.

    Including overload protection in your communication system designs will prevent failures from damaging environmental disturbances. The benefits of reduced service costs and an enhanced reputation for product quality far outweigh the small cost for the additional components added to the product designs.

  8. Tomi Engdahl says:

    IEEE standard PoE comes always with nominal around 48V voltage (44-57V or 50-57V DC) and different current ratings (350, 600 or 960 mA per wire pair)
    Non-standard proprietary systems can use different voltage levels (typically between 5V and 50V, usually, 12V, 24V or 48V DC).
    I have built stuff for both types.

  9. Tomi Engdahl says:

    Designed to leave most GPIO pins free and not block the SoC, UCTRONICS’ PoE HAT Mini is an interesting add-on for Power-over-Ethernet.

    UCTRONICS’ PoE HAT Mini Adds Power-over-Ethernet to a Raspberry Pi in Tiny Footprint

    Designed to leave most GPIO pins free and not block the SoC, UCTRONICS’ PoE HAT Mini is an interesting add-on for Power-over-Ethernet.


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