Würth Elektronik

LAN Transformers and Modular Jack Connectors

Würth Elektronik's LAN transformers offer multiple Ethernet solutions

Image of Würth Elektronik's LAN Transformers and Modular Jack ConnectorsWürth Elektronik's WE-LAN transformers are designed with at least one transformer and one common mode choke in each channel. The LAN transformer portfolio consists of the WE-LAN series with Power over Ethernet (PoE) up to 150 W and speeds up to 1 Gbit/s. The WE-LAN 10 G transformers with 10GBase-T and PoE+ over four pairs up to 150 W. The WE-LAN AQ transformers are manufactured by a fully automated process with Ethernet speeds up to 1 Gbit/s.

Würth Elektronik's WR-MJ modular jacks offer a broad range of connector types that comply with Ethernet and other communications standards. Modular jack connectors are the connector of choice for local data communication. The WR-MJ connectors are available in multiple versions, ranging from plastic to shielded options in vertical, horizontal, 45 degree, and 47.5 degree orientations. The jack design is in accordance with FCC regulation and compatible with IEEE standards IEEE 802.3u, 802.3z (8P8C RJ45), and PoE++-compatible up to 100 W (IEEE 802.3bt).

Würth Elektronik also offers the WE-RJ45 LAN transformers built with an RJ45 connector with integrated transformer/common mode choke available in multiple configurations, THT and SMT, and with or without LEDs. The WE-RJ45 LAN features PoE up to 50 W and speeds up to 10 Gbit/s.

Application Notes
LAN Transformer Features
  • Compliant with IEEE 802.3 standards: 802.3af, 802.3u, 802.3ab, 802.3at, 802.3bt, 802.3an
  • SMT
  • Inductance of 120 µH up to 350 µH
  • 1:1 ±2% turns ratio
  • -1.1 dB typ. insertion loss at 1 MHz to 100 MHz
  • -38 dB typ. crosstalk at 1MHz to 100MHz
  • -38 dB typ. differential to common-mode rejection at 1 MHz to 100 MHz
  • Return loss:
    • -18 dB min. 30 MHz
    • -14 dB min. 60 MHz
    • -12 dB min. 80 MHz
    • -10 dB min. 100 MHz
WR-MJ Modular Jack Connector Features
  • Jack design in accordance with FCC regulation
    • Mates all FCC plugs
  • 4P4C, 6P2C, 6P4C and 8P8C configurations
  • Stacking up to 2 x 6
  • Ethernet, Cat 3, Cat 5, Cat 6, and Cat 6a
  • Discreet solution for Ethernet protocol (8P8C RJ45)
    • Smaller footprint
    • High flexibility in PCB design
    • THR compatibility
    • Potentially better crosstalk performances
WE-RJ45 LAN Features
  • RJ45 connector with integrated transformer/common mode choke
  • PoE up to 50 W and speeds up to 10 Gbit/s
  • Available in SMT and THT 
  • Compliant with standards: IEEE 802.3u, IEEE 802.3ab, IEEE 802.3af, IEEE 802.3at, and IEE 802.3bt
  • Improved common mode rejection (CMRR) due to additional NiZn cores 

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Updated: 2025-11-11
Published: 2023-05-22

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