Timings during 1-Event Classification
It seems intuitive at first thought that the time for which the PD turns on its class-current-sink, is, or should be, somehow controlled or defined by the IEEE standard. But in fact, we cannot assume any timers are present inside the PD during classification—for the simple reason the PD has minimal power available at this point and is not expected to support potentially power-hungry circuitry (that was at least the reasoning at the time of the AF standard). The PD is therefore designed mainly to just respond to the applied voltage levels, both during detection and classification.
On that basis, it is the time for which the voltage source is applied by the PSE which is actually governed by the standard, ...
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