Highly integrated, IEEE 802.3af compliant, Power over Ethernet controller

Targeted at wireless access points, voice over IP phones, radio frequency identification tag readers, point-of-sale terminals, security systems and cameras, the Si3400 eliminates up to 25 external components compared to competing solutions. This reduces the PCB footprint by 30 to 50 percent and the total BOM by as much as $1.50. Fewer external components improve overall product reliability and simplify the supply chain for customers. The Si3400 enables PoE system designers to focus on system-level product differentiation and customization rather than spending valuable time and resources on external components and challenging design issues, such as analog layout or meeting radiated emissions specifications.

Silicon Laboratories achieves unparalleled integration with the Si3400 by leveraging high-voltage and mixed-signal design expertise to deliver a unique, feature-rich and versatile architecture that is fully compliant with IEEE 802.3af, while adding features beyond the standard’s base requirements. For example, with direct access to the line side voltages from the Ethernet cable, the integrated diode bridges enable a proprietary early power loss indicator, which provides adequate time to save operating and status information before safely shutting down the powered device. The diode bridges also allow a direct connection to the RJ-45 connector, which minimizes the PCB trace lengths between the connector and the Si3400. This helps limit radiated emissions, speeding certification required by PoE products. In addition, the integrated transient suppressor activates protection circuitry when high voltages are detected, improving overall device robustness and reliability.

The Si3400 controller includes a complete PD interface with programmable classification and detection signature circuitry, a switching regulator controller, dual current-limited hot swap switch, comprehensive protection circuitry including thermal shutdown capability and support for both non-isolated and isolated applications. The Si3400 has been designed to operate seamlessly with both 802.3af compliant Power Sourcing Equipment (PSE) and pre-standard (legacy) PSEs that do not comply with the standard’s inrush current limits.

Pricing for the Si3400 begins at $2.48 in quantities of 10K. Packaged in a lead-free (RoHS compliant), 5 x 5 mm, 20-pin QFN, samples are available now, and production is scheduled for Q3 2006. An engineering evaluation board (Si3400-EVB) is also available now and will be followed by a complete Ethernet system evaluation kit in August.