Single port PoE interface adds integrated dc-dc controller
November 5, 2007 -- Silicon Laboratories Inc. has introduced a dual-function, single-port Power over Ethernet (PoE) controller chip with an integrated dc-dc controller for power sourcing equipment (PSE).
November 5, 2007 -- Silicon Laboratories Inc., a provider of analog mixed-signal ICs [integrated circuits] has introduced a dual-function, single-port Power over Ethernet (PoE) controller chip with an integrated dc-dc controller for power sourcing equipment (PSE). By combining these two functions, the company says its Si3460 device can dramatically simplify development efforts for designers of PoE applications such as home gateways, set-top boxes, cable modems, DSL modems and Voice over IP (VoIP) systems.
According to the company, unlike competitive single-port platforms providing only a PSE interface, the Si3460 integrates a dc-dc digital power controller to generate a negative 48V PSE supply, ensuring safety extra low voltage (SELV) compatibility with legacy telephony ports within the system. The company contends the Si3460 can reduce the total PSE solution cost to less than $2.00 while preserving the use of low-cost 12V power supply adapters and typical point-of-load (POL) dc-dc converters.
The company notes that the Si3460 controller also provides extensive protection such as inrush current control, input under voltage lockout (UVLO), short circuit protection and current limiting to ensure robust, fail-safe operation during all operating conditions. The Si3460 also supports Fast (10/100 Mbit/sec) and Gigabit Ethernet endpoints and midspans and is pin configurable to supply maximum power (15.4W, Class 0) PSEs, or limit power to IEEE class levels one through three.
The Si3460-EVB reference design, which includes all the recommended external components for a complete single-port PSE design, also provides IEEE 802.3af-compliant detection, classification and disconnect functionality.
"The Si3460 uniquely solves the two main challenges facing PSE systems designers: implementing a fully compliant IEEE 802.3 PSE interface and easily and safely generating the negative 48V PSE power supply from an existing low-voltage supply," comments Dave Bresemann, vice president of Silicon Labs. "In combination with the Si3400/01 controller for PDs, Silicon Labs provides end-to-end solutions for PoE."
The Si3460 is sampling now with volume production set for January 2008. The device is packaged in a RoHS compliant, Pb-free, 3 x 3-mm QFN package. Pricing starts at $1.05 each in quantities of 10K units. The comprehensive Si3460-EVB reference design kit is also available from the company for $95.00.