I have tried it on an HP branded 2920, an Aruba branded 2920 and an Aruba 2530 switch which all support POE+ 802.3af and up to 30W per port. I have tried 3 different AP305c's.
The AP is connected to an aruba/hp 2920 POE+ switch and the specs show it support both at and af. The switch shows the AP drawing 5.2W and the port to be PLC Class/Type: 4/2.