Tool/software:
Hi,
We use the TPS23861PW for the new design.
Now our end customer needs to use the 802.3af standard network camera.
We use TPS23861PW to make 802.3af (PoE) according to the reference design of the "Automatic 4-Port Operation Schematic", using a power supply voltage of 48V.
The waveform of AT and AF is diffenent in the datasheet, but we measured the the actual waveform is same as the waveform of AT;
We wants to know if we need to set the paramater based on AF protocol, thanks.
Hi Zhang,
Can you share the waveforms you are referencing as well as the expected behavior?
For af standard PoE if the PSE contorller measures a current during classification that results in a Class 4 signature, the PSE will do 2-event classification which is enabled by default. If the PD that is being connected is an AT device, the PSE will negotiate AT unless otherwise set. If the far end PD being connected is AF standard PD, the PSE will only do 1-event classification.
If you wish to limi the PSE to AF standard, you will need to configure register 21h (Two-Event Classification) to disable 2-event so you only do 1-event classification (which is AF standard).
Regards,
Brandon
