PoE interface chip has DC/DC controller

Silicon Laboratories Inc. has announced what it claims is the industry's first dual-function, single-port PoE controller with an integrated DC/DC controller for power sourcing equipment (PSE).

By combining these two functions, the Si3460 is designed to simplify development efforts, reduce system costs and eliminate specification compliance challenges for designers of a broad range of emerging PoE applications such as in home gateways, STBs, cable modems, DSL modems and VoIP systems.

The Si3460 integrates a DC/DC digital power controller to generate a negative 48V PSE supply. This helps to ensure safety extra low voltage (SELV) compatibility with legacy telephony ports within the system.

According to Silicon Labs, the Si3460 reduces the total PSE solution cost to less than $2 and preserves the use of low-cost, 12V power supply adapters and typical POL DC/DC converters. 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 functions.

The Si3460 controller provides protection such as inrush current control, input under voltage lockout (UVLO), short circuit protection and current limiting to ensure fail-safe operation during all operating conditions. The Si3460 also supports Fast (10/100Mbps) 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 device is packaged in a RoHS compliant, Pb-free, 3mm x 3mm QFN package.

Pricing starts at $1.05 each in quantities of 10,000. The devices are sampling now with volume production slated for January 2008. The Si3460-EVB reference design kit is available now for $95

- Ismini Scouras
eeProductCenter