Power-over-Ethernet design simplified by evaluation module and reference design

August 18, 2014 // By Graham Prophet
Texas Instruments has introduced a two-layer-PCB (Power-over-Ethernet) PoE power sourcing equipment (PSE) evaluation module and design based on its TPS23861 PoE controller.

The quad-port controller and reference design reduce development time and cost when creating PoE-enabled network video recorders, IP phone switches and wireless base stations. The design reduces PoE development costs: the evaluation board features two controllers with associated circuitry on a two-layer printed-circuit board (PCB), minimising material and build costs associated with multiple boards. "Plug and play" operation comes with the module's auto mode, eliminating the need for host control. The design is tested to be IEEE compliant, and does not exceed 400 mW in any operating condition. An external-FET architecture allows the design engineer to select the FET that best meets size, cost, and efficiency requirements. A four-point detection feature avoids system damage by preventing erroneous start-up.

For custom power management programmability and configuration, the TI Design's motherboard provides interfaces for two optional boards, the MSP-EXP430G2 LaunchPad and USB-to-GPIO Interface Adapter.

In a 28-pin TSSOP package, the TPS23861 PoE PSE controller costs $3.40 (1,000). The TPS23861EVM-612 evaluation module is $299 and includes a downloadable PI Commander graphical user interface. A fully tested and proven TIDA-00290 PoE reference design with schematic, bill of materials and design files is also available for download.

Texas Instruments; www.ti.com/poedesign-pr