-
Product Center
-
-
-
Unmanaged Industrial Switches(Extended Temp)
Unmanaged Industrial Switch
L2 Managed Industrial Switches
L3 Managed Industrial Switches
TSN Industrial Switch
Managed Industrial PoE Switch
M12 Industrial Switch
Industrial 100-Mbps Transceiver
Industrial Gigabit Transceiver
Unmanaged Switch
L2 Managed Switches
Standard PoE Switches
Non-standard PoE Switches
Managed PoE Switch
Managed Domestic Switches
Unmanaged Waterproof Switches
Managed Waterproof Switches
100M Fiber Optic Transceivers
Gigabit Fiber Optic Transceivers
Fiber Optic Transceiver Chassis
Pure Telephone Optical Terminals
Telephone&Ethernet Optical Terminals
Integrated Service Telephone Optical Terminals
HDMI Video Optical Terminals
SDI Video Optical Terminals
VGA Video Optical Terminals
DVI Video Optical Terminals
3.5mm Interface Audio Optical Terminals
RCA Interface Audio Optical Terminals
XLR Interface Audio Optical Terminals
Commercial-grade Dry Contact Optical Terminals
Industrial-grade Dry Contact Optical Terminals
RS485 Date Optical Terminals
E1 Over IP
Voier Over IP
Pure E1 Optical Terminals
1+1 Fiber Back-up Optical Terminals
4~30 Channels PCM Multiplexers
Ethenet Over 1~16*E1 Converters
1~32 Serial Port Servers
Industrial 4G Routers
Industrial 5G Routers
2.4G/5.8G Wireless Bridge
Wireless AC Controller
Gigabit Optical Modules
Power Adapter
Rail-Mounted Power Supply
Fiber Optic Pigtail
Terminal Box
News Details
Three Standards for PoE Power Supply
Release time:
2026-03-02
Three standards for PoE power supply:
1. IEEE 802.3af Standard (PoE)
The IEEE 802.3af standard was published in 2003. As shown in Table 1, the DC voltage specified by the IEEE 802.3af (PoE) standard ranges from 44 to 57 V, with a typical value of 48 V. The typical output power is 15.40 W. Under the IEEE 802.3af standard, the Power Sourcing Equipment (PSE) can supply up to 12.95 W of electrical power to the Powered Device (PD).
2. IEEE 802.3at Standard (PoE+)
Due to the IEEE 802.3af standard, the PoE power consumption of powered devices (PDs) is limited to 12.95 W, which in turn restricts the scope of Ethernet‑based power delivery applications. To address this limitation on power budgets, the IEEE 802.3at standard—also known as PoE+—was introduced in 2009, specifying a maximum power output of 30 W. Compared with 802.3af, IEEE 802.3at delivers more than twice the power, allowing PDs to draw up to 25.50 W, while the Power Sourcing Equipment (PSE) can supply over 30 W.
3. IEEE 802.3bt (PoE++)
Although the power rating of 802.3at has increased, the IEEE 802.3af/at standards cap the PoE power consumption of powered devices (PDs) at 25.5 W, making them suitable only for standard applications such as ordinary cameras and IP video phones. For higher‑power devices—such as high‑speed PTZ cameras, all‑in‑one cloud desktops, point‑of‑sale (POS) terminals, and LED lighting—the available power is far from sufficient.
To meet the higher power requirements of PD devices, the new IEEE 802.3bt standard—also known as PoE++ or 4PPoE—was released in 2018. This standard revises the earlier PoE and PoE+ specifications, extending power delivery up to 90 W. Additionally, 802.3bt is backward compatible with both 802.3at and 802.3af. A lower‑power PD device compliant with 802.3at or 802.3af can connect to a higher‑power 802.3bt PSE and deliver up to 90 W over four or more pairs of CAT5e cabling.
Guangzhou Guangqiao Communication Equipment Co., Ltd. specializes in the research, development, and manufacturing of communication equipment. Its main product lines include industrial switches, industrial Ethernet switches, industrial PoE switches, fiber optic transceivers, fiber optic switches, multi‑port transceivers, telephone optical terminals, video optical terminals, protocol converters (bridges), PCM multiplexing equipment, PDH optical terminals, E1 protection switching devices, serial‑port optical terminals, SFP optical modules, and more. Contact numbers: 400‑8866‑640, 020‑82319301, 020‑82319302. Quality first, competitive pricing.
Related Information
How is the backplane bandwidth of an industrial switch calculated?
How is the backplane bandwidth of an industrial switch calculated?
Learn more
Beijing–Tianjin–Hebei, Henan, Shanxi, Inner Mongolia, and Sichuan:+8613719208595
Fujian, Guangxi, Hainan, Yunnan, Guizhou, and Jiangxi:+863760887412
Heilongjiang, Jilin, Liaoning, Inner Mongolia, Hunan, Chongqing:18126729399
Jiangsu, Zhejiang, Shanghai, Shandong, and Anhui:+8618198851696
Shaanxi, Gansu, Ningxia, Qinghai, Xinjiang, and Tibet:+8618198851697
Guangdong Region:+8613302232639 +8618903052902
3rd Floor, Elevator No. 1, Building B, Guangzheng Science and Technology Park, No. 11, Nanyun Fifth Road, Huangpu District, Guangzhou City