O'Reilly logo

Power Over Ethernet Interoperability Guide by Sanjaya Maniktala

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Device Dependency in the AF Standard
Consider the fact that in the AF standard, as per Table 33-5, page 42, ICUT is expressed as a range extending from PCLASS/VPORT to 0.4 A. But, looking carefully also at Figure 33C.6, page 97 of the AF standard, we realize that what is really being implied by stating it in this manner is that the systems/IC designer needs to target a nominal value for ICUT centered somewhere roughly in the middle of this range (say 375 mA), and also ensure that the min and max values of this parameter ICUT are always within the prescribed limits—PCLASS/VPORT to 0.4 A, all tolerances, drifts, and so on considered. The understanding is that whenever the actual set threshold of a given PSE device is exceeded, its internal comparator ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required