Vitesse-based Gbit Ethernet switches support PoE

A Silicon Laboratories product story

Edited by the Electronicstalk editorial team Nov 11, 2009

Silicon Laboratories and Vitesse Semiconductor have released multiple reference designs to enable easy upgrades for Vitesse-based Gbit Ethernet switches.

These upgrades will allow the Gbit Ethernet switches to support the recently ratified IEEE 802.3at Power over Ethernet (PoE+) standard.

Two new reference designs combine Silicon Laboratories' highly integrated, energy-efficient PoE Power Sourcing Equipment (PSE) controllers and the Vitesse E-Stax and Sparx Gbit Ethernet switching chipsets for 24-port stackable and five- to 24-port workgroup and desktop switches, respectively.

The first joint design is a PSE daughtercard for E-Stax and Sparx-II switches.

The plug-in daughtercard features an isolated I2C interface, self-contained operation from an isolated PoE supply (54V nom.) and efficient thermal profiling.

The design supports 24 ports at up to 30W each with full IEEE 802.3at compliance.

Multiple daughtercards can interoperate on a single I2C host interface for high port-count scalability.

Switch-host software integration and an independent PoE power supply enable a single-switch motherboard design appropriate for PoE and non-PoE SKUs.

The second design is a single-motherboard implementation for the Sparx-G8e switch.

Supporting eight ports of PoE (15.4W) or PoE+ (30W) capability and Vitesse's web-based configuration and power-management GUI, this complete PoE-enabled switch is intended for applications such as desktop switches, VoIP telephony, wireless-access points, industrial networking, video surveillance and security systems.

Both reference designs include schematics, bill of materials and comprehensive PCB layout files for fastest time-to-market and design success.

Silicon Labs' Power Manager Software Development Kit (SDK) allows system developers to quickly develop highly differentiated PSE systems with sophisticated power-management features to minimise power-supply costs and maximise energy efficiency.

Based on Silicon Labs' Si345x PoE+ PSE controller family, designers can take advantage of real-time power-measurement capabilities.

The Si345x incorporates high-precision current and voltage-measurement capability to monitor the power consumed by each port, enabling systems to maintain tighter control of power allocation, which translates to smaller power supplies and lower supply overhead and gives system administrators visibility into how much power is allocated to and consumed by each port in their network.

Link layer discovery protocol (LLDP) power management algorithms are implemented at the system level, enabling dynamic power allocation.

Vitesse's E-Stax products feature its Vstax cabling technology, a scalable high-speed 24+4 port configuration, a performance-driven architecture and a rich integrated feature set to deliver low-cost Gbit Ethernet for OEM and ODM customers.

The Sparx unmanaged and smart web-managed switches eliminate the need for external processing and memory found in fully managed switches, allowing developers to deliver a smart switch with advanced Layer-2 capabilities at a fraction of the cost of a fully managed switch.

Sparx switches also include Vitesse's Ecoethernet technology, which delivers green savings equivalent to more than 400mW per port.

Both product families are ideal for Carrier Ethernet applications as they support synchronous Ethernet with SSM according to ITU-G.8264/Y.1362 and offer fast protection switching with switching times significantly below the 50ms telecom requirement.