Optical receivers support Fibre Channel

Vitesse Semiconductor has introduced three optical receivers that support the emerging 4Gbit/sec Fibre Channel standard.

The optical receivers incorporate Vitesse’s new low jitter Transimpedance Amplifiers (TIA).

The majority of Storage Area Networks (SAN) deploying Fibre Channel systems will be 4 Gbit/sec enabled by 2006. Critical to acceptance of this new INCITS/T11 approved standard is backward compatibility and comparable cost to existing 1 Gbit/sec and 2 Gbit/sec solutions. The VSC7773 meets this requirement by allowing OEMs to design a single SFP-8074 compliant module for 1 Gbit/sec, 2 Gbit/sec and 4 Gbit/sec Fibre Channel and Gigabit Ethernet applications.

The VSC7773 integrates a photocurrent monitor that reports on received optical power as required by the SFP digital diagnostic standard outlined in the SFF-8472 specification. Typically, the monitor is implemented via discrete components residing outside of the receiver optical sub-assembly (ROSA), consuming valuable module board space and adding to the module cost. Vitesse has simplified the design by integrating the photocurrent monitor feature on the TIA die. This function enables active optical alignment during the module manufacturing process.

The VSC7971 and VSC7973 offer the same functionality as the VSC7773, but are designed to operate at 1 Gbit/sec to 2.5 Gbit/sec. All of the new receivers operate from a single 3.3V power supply and consume only 25mA of supply current, representing a 15% savings versus competitive devices. This is critical for system vendors who may stack up to 32 SFP modules on a single Storage Area Network or telecom rack. The receivers also offer 10% higher overload protection and 40% greater transimpedance gain versus competitive devices, resulting in greater system architecture flexibility.

The VSC7971, VSC7973, and VSC7773 receivers are available assembled in TO-46 package with an integrated PIN detector. The receivers are available in 850nm or 1310nm/1550nm wavelength ranges to support both shortwave (SX) and long wave (LX) applications. All of the devices are 100% tested at-speed to demonstrate that all DC and high-speed specifications are met.

Vitesse also offers the TIAs in die form for those designers who wish to assemble their own receivers. Vitesse plans to expand this product family by offering these products in a ROSA with plastic or metal LC ferrules in the near future. The devices support an extended temperature range of -40 degrees C to +85 degrees C.