• Latest
  • Trending

Power Over Ethernet (PoE) and PoE+

September 20, 2022

Microwave Multi Line Connectors Mounting and Handling Precautions

March 27, 2023

Samtec New Interconnects Enhances Power and Signal Integrity

March 21, 2023
PCNS Passive Components Symposium 11-14th September 2023

PCB Via Design Selection; Plugging-Filling-Tenting

March 20, 2023

Lemo Releases New Multi Coaxial High Frequency Connector

March 2, 2023

Würth Elektronik Introduces Crimp SKEDD Connectors

March 1, 2023

binder Offers Sensor Connectors in Stainless-Steel to Protect Against Corrosion

March 1, 2023

Board-to-Board Connection & Antennas HF Connection

February 20, 2023

How to Ensure Board-to-Board Connectors Meet High-Speed Automotive Assembly and Use Requirements

February 16, 2023

Amphenol Enhanced its ePower-Lite EV Line to Include 3-Pole Connector

February 15, 2023

BASIC PCB Design Rules – Layout

February 15, 2023

Connector Inrush Current Explained

February 3, 2023

M8 Connectors for Smart Farming Applications

January 31, 2023
  • Privacy Policy
inter-connection blog
  • NEWS
  • Knowledge base
  • Sister Sites
    • Passive Components Blog
    • PCNS Symposium
    • The Passives Times
    • EPCI Home
  • About
No Result
View All Result
  • NEWS
  • Knowledge base
  • Sister Sites
    • Passive Components Blog
    • PCNS Symposium
    • The Passives Times
    • EPCI Home
  • About
No Result
View All Result
inter-connection blog
No Result
View All Result

Power Over Ethernet (PoE) and PoE+

September 20, 2022
A A

Definition
Power Over Ethernet (POE) technology allows VoIP phones, WLAN access, IP camera … to receive power as well as data over existing LAN cabling without modifying the existing system.

Establishment of an international standard, IEEE802.3af allows an explosion of POE installation all over the world, which was not possible while old proprietary standards were existing together. The cost of adding power supplies to Ethernet switches is getting smaller and smaller. Figure 2.159 shows a typical POE installation.

Fig. 2.159: Typical POE installation

Today, most electronic applications require both data connectivity and power supply. The most familiar example is telephone which is powered via the same twisted pair that carries the voice since its invention. Did you ever plug your telephone to power before they become hand free?! Of course not so the aim of POE standard is to standardize how to do the same with Ethernet devices without modifying the communication protocol.

There were many technical constraints. A complete recognition protocol had to be defined to detect whether connected systems could receive power (without damaging them), classify their power ratings, and define the way of transmitting voltage and current.

Classification and Applications
This article does not aim to go into too much detail about POE but the attached classification gives the main characteristics of the POE & POE+ standards (POE+ being able to carry more power, up to 25.5 W like for a bigger IP camera with zoom …)

Tab. 2.18: POE classification
Fig. 2.160: Typical POE applications (left: IP camera/right: IP phone)

The IEEE standards are 802.3af and 802.3at respectively for PoE or PoE+.

Fig. 2.161: Synopsis of a POE system

PSE: (Power Sourcing Equipment) the device that provides power.
PD: (Power Device) this is the device that receives power.

Usually, the distribution is as follows:

PHY side: TD+/–, RD+/–, PHY ground, LED pins (as LED are driven by the PHY)
Cable side: Power pins (PoE), RJ45 pins.

What about modular jacks, what does it imply on this respect?
The key point is the insulation which is carefully controlled and the interface must withstand 1500 Vrms 1 min. PHY side and cable side (remember Figure 2.155) must be insulated from each other.

The distance between RJ45 pins and between RJ45 pins & shielding must be sufficient to stand this voltage. In this case above 1.4mm.

Problems comes often from the LED pins that are in general too close to the shielding.

Summary
To stand POE standard, pins must always have a minimum distance of 1.4 mm between each other and with the shielding too. Special care must be on LED pins which are often too close to the shielding.

A connector does not have absolutely to be used with transformer to be POE compatible (a standard connector without LED should fit) but it is often necessary (for the LED one) since transformer connector designer often included the POE parameter in their concept (much more than the non-filtered one which were developed earlier)

Related

Source: Wurth elektronik
Next Post

Connector Applications

Signal Applications

Power Applications

Popular Posts

  • Crimped Connections

    0 shares
    Share 0 Tweet 0
  • Basic Principles of Connectors

    0 shares
    Share 0 Tweet 0
  • Space Saving Molex Connector in AR/VR System designs

    0 shares
    Share 0 Tweet 0
  • THR (Through Hole Reflow) Technology: Introduction & History:

    0 shares
    Share 0 Tweet 0
  • The Electrical Interface: Contact Resistance

    0 shares
    Share 0 Tweet 0

Archive

2023
2022

  • About
  • Inter-Connection News
  • Knowledge base
  • NEWS
  • Privacy Policy
  • Sister Sites

© 2023 EPCI - Premium Passive Components & Inter-Connect News

No Result
View All Result
  • About
  • Inter-Connection News
  • Knowledge base
    • Applications
    • Basic Principles of Connectors
    • Design Selection Assembly
  • NEWS
  • Privacy Policy
  • Sister Sites

© 2023 EPCI - Premium Passive Components & Inter-Connect News

This website uses cookies. By continuing to use this website you are giving consent to cookies being used. Visit our Privacy and Cookie Policy.