Texas Instruments and Wurth Electronics Midcom Create Suite of Power-over-Ethernet Applications

Wurth Electronics Midcom Inc. recently designed in three Power-over-Ethernet (PoE) reference designs with Texas Instruments (TI).

Featured on the suite of PoE designs from Texas Instruments is a WE-LAN transformer module and at least one WE-PD4 inductor. The WE-LAN transformer module provides coupling and impedance matching from the IC to the Ethernet line and provides exceptionally low crosstalk. It also has a high level of common mode noise rejection from the integrated common mode choke and provides low insertion and return losses. The PoE LAN transformer module comes in a compact, surface mount design and has an operating temperature from -40 to 85°C.

Highlighted on the TPS23750-HPA108 is a custom made Wurth Electronics Midcom flyback transformer (750310040) designed specifically for Texas Instruments. The flyback transformer comes in a compact 12 pin, EFD15 SMD design. It has a low leakage inductance of 2.4µH for high efficiency, and a primary inductance of 146µH. The transformer carries 500VDC isolation and has low DCR on all windings with an operating temperature of -40 to 125°C.

The designs: TPS23750-HPA107EVM, TPS23750-HPA108EVM and the TPS23753AEVM-004, implement IEEE 802.3af-compliant, class-3, power interface and a DC/DC switching converter using the Texas Instruments controllers in a typical PoE configuration. The layouts come in buck and flyback topologies, and the IC contains a complete PoE interface. The front end of the PoE includes detection, classification, as well as under voltage lockout and current inrush control. The PoE switch is included within the IC. Applications include IP telephones, wireless access points and wired IP cameras.