Introduction to the PoE Certification Program
The Power over Ethernet industry now has an easy way to identify which PoE systems are interoperable. The Ethernet Alliance has driven a new certification program that TI has taken a part in, to ensure many of our PoE designs are truly “plug and play” for PoE customers.
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Welcome to a high-level introduction to the PoE certification and logo program. This new program was created under the direction of the Ethernet Alliance, of which TI is a member. In short, the industry needs an easy way to know if any one PoE system is interoperable. The program was devised with three goals in mind-- to eliminate interoperability problems and minimize end user frustration and lower debug support costs. Increased plug and play capabilities is the ultimate goal here.
While end users desire an easy identification of tested products, the industry seeks to minimize interoperability issues which tarnish the PoE brand image. Beyond this, there's also the practical matter of debugging interoperability issues when they arise. Through the logo and the test suite behind it, debug is accelerated via the initial question. Do both sides of the cable have an ethernet alliance PoE logo? If one side does not, debug efforts will naturally start there. This will bring significant cost savings across the PoE business channel.
The need for such a logo has existed for years and is about to grow exponentially due to a forecasted increase in demand coming from expansion into new markets enabled by the forthcoming IEEE 802.3 BT standard. The Ethernet Alliance, anticipating this rapid growth in equipment deployment, reached out to its members and drove the certification program I'm discussing today.
If requiring guidance on how to secure a logo, please watch the webinar available from the Bright Talk website and/or refer to the white paper link shown here, as this video will not cover that topic in detail. In one sentence, the EA logo means the end equipment listed has passed the Ethernet Alliance certification test plan. This plan is based on IEEE standard 802.3-2015 POE specifications and can be found and reviewed on the EA website. Products which have passed this testing have increased confidence of interoperability between certified products.
Let's first discuss logos intended for powered devices, also known as PDs. First, the left-hand side depicts an arrow coming into a white box. This is intended to graphically denote that PDs receive power. The number indicated in the right-hand box communicates the maximum class power the PD has been tested to from an interoperability perspective.
Moving on to the power sourcing equipment, or PSEs, we see that the logo is essentially inverted. This is to show the symbiotic relationship between the two ends of a PoE system. As shown here, the logo depicts an arrow coming out from the right-hand white box. This is intended to graphically denote that PSEs are responsible for sending power.
The number indicated in the left-hand box communicates the maximum class power the PSE has been tested to from an interoperability perspective. In the larger view, as long as the PSE class power denotation is equal to or higher than the PD class power denotation, the two systems in discussion are EA tested and interoperable. In this case, 4 is greater than 1.
The full suite of possible PSE PD class level marking combinations are shown here. For more descriptions of the logos and how to interpret them, please refer to our blog on the same subject. As mentioned in the previous slide, logo arrows flow into or out of white boxes. This is intentional, as certifications are granted at the white box level, not at the individual PSE IC or PD IC level. Due to critical interactions between various parts of a PoE system, it is possible for the same IC to have high interoperability in one design and troubling behavior in another one. Of course, it is also possible for an IC itself to fail interoperability testing in all situations if poorly defined.
In either case, by testing at the system level, the installer or end user can have increased confidence in the equipment's interoperability. Issues coming from system software or transformer design, for example, are captured in this testing approach. As such, logo licenses are awarded at the white box level, or in the case of IC vendors, at an EVM or reference design level.
Using the TPS2388 PSE controller as an example, there is no logo published on the TPS2388 product page and/or datasheet. Instead, the logo appears in the TPS2388 EVM-612 tool folder and user's guide. It was mentioned earlier that a new PoE standard is in the final stages of ratification. Indeed, the highly anticipated IEEE 802.3 BT standard is expected to be published this September. With it will come four new power classes-- classes 5 through 8, as shown here.
These new power levels will scale PoE's reach up from a maximum of 30 watts sent, 25.5 watts delivered, to a maximum of 90 watts sent, 71.3 watts delivered. With that said, the standard is not complete today, and neither are the various test suites required to demonstrate compliance and interoperability. Thus, the initial EA logo certification we discussed today is limited to class 1 through 4.
Some within the industry refer to this release as Gen 1. Work is already in motion to release a Gen 2 test plan, which will include the new IEE 802.3 BT class levels. Be on the lookout for announcements regarding Gen 2 availability from the EA.
Texas Instruments is excited about the new EA logo certification program, as evidenced by TI being the first IC vendor to earn a logo license. Today we have eight licensed EVMs or TI designs ready for customers to reference or directly copy and paste when starting projects of their own. These designs can be found by typing www.ti.com/logo into your internet browser or by visiting the EA's official certified products registry.
This concludes our brief introduction to the Ethernet Alliance PoE certification program. Listed here are some suggested links for additional research and information. All of them can ultimately be found from the Ethernet Alliance home page-- ethernetalliance.org/ea. So what are you waiting for? Get started today by visiting our suite of logo designs available at www.ti.com/logo.