PoE controller combines two functions

Edited by the Electronicstalk editorial team Nov 6, 2007

The Si3460 dramatically simplifies development efforts, reduces system costs and eliminates specification compliance challenges for designers

Silicon Laboratories has released a dual-function, single-port Power over Ethernet (PoE) controller with an integrated DC/DC controller for power sourcing equipment (PSE).

By combining these two functions, the Si3460 dramatically simplifies development efforts, reduces system costs and eliminates specification compliance challenges for designers of a broad range of emerging PoE applications such as in home gateways, set-top boxes, cable modems, DSL modems and Voice over IP systems.

Unlike competing single-port solutions providing only a PSE interface, the Si3460 integrates a DC/DC digital power controller to cost-effectively generate a negative 48V PSE supply, ensuring safety extra low voltage (SELV) compatibility with legacy telephony ports within the system.

The Si3460 preserves the use of low-cost, 12V power supply adapters and typical point-of-load (POL) DC/DC convertors.

The Si3460-EVB reference design, which includes all the recommended external components for a complete single-port PSE design, also provides IEEE802.3af-compliant detection, classification and disconnect functionality.

The Si3460 controller 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 (10/100Mbit/s) and Gigabit Ethernet endpoints and midspans and is pin configurable to supply maximum power (15.4W, Class 0) PSEs, or limit power to IEEEclass levels one through three.

The Si3460 solves the two main challenges facing PSE systems designers: implementing a fully compliant IEEE802.3 PSE interface and generating the negative 48V PSE power supply from an existing low-voltage supply.