Vitesse Unveils Industry's First SFP Chipset for 4 Gbps Fibre Channel

8/23/2004 - Vitesse Semiconductor Corporation (NASDAQ: VTSS), announced the availability of the industry’s first chipset specifically designed for next-generation, multirate Fibre Channel and Gigabit Ethernet SFP modules. This SFP chipset sets a new standard in functionality and performance by being the first solution commercially available with rate selection capabilities for 1 Gbps, 2 Gbps, and 4 Gbps. This two-chip solution reduces module chip count when compared with current market solutions and provides enhanced SFP/SFF-8472 compliant digital diagnostic capabilities that are critical for functionality and design flexibility. The chipset includes the VSC7964, a monolithic Laser Driver and Post Amplifier, and the VSC7977, a bandwidth selectable Transimpedance Amplifier.

According to Dell’Oro Group, worldwide shipments of Gigabit Ethernet Fiber ports and Fibre Channel Switch ports are expected to grow to over 17 million by 2008. The SFP/SFF form factor, with its small footprint and integrated digital diagnostics, has become the dominant optical module for storage and communication systems up to 2.5 Gbps.

SFP Chipset Saves Money and Time
The VSC7964 and VSC7977 chipset architecture and pin placement has been optimized to reduce the Bill of Material cost and to simplify the assembly process to the point where all components, both active and passive, can fit on a single side of a four-layer printed circuit board. This chipset also requires 50% less external passive components than competitive solutions. The VSC7964 is the first device to integrate the VCSEL Laser Driver and Post Amplifier into a single integrated circuit. The driver features automatic power control loop, adjustable negative peaking control, six integrated digital-to- analog converters (DACs), and a temperature sensor - all of which reduce the need for external components.

“This chipset allows for maximum performance and flexibility while meeting the aggressive cost targets of next-generation SFP modules,” said Brad Sakai, product marketing engineer for Vitesse’s Transport Products Division. “The true multirate capability allows SFP modules to finally meet the Fibre Channel and Gigabit Ethernet standards specifications for all data rates with a single module.”

Superior Optical Performance
The VSC7964 has demonstrated superior performance at all data rates when compared against competing solutions. With measured rise and fall times on both the transmitter and receiver of less than 40 ps, the VSC7964 exhibits 40% margin to the 4G Fibre Channel eye mask and greater than 50% margin to the 1G/2G eye mask. The sensitivity of the post amplifier is 3 mV differential, with a crosstalk penalty of less than 0.1 dB, corresponding to an optical sensitivity of –21 dBm at 4 Gbps.

The VSC7977 optical sensitivity at the 4 Gbps data rate adds over 6 dB of margin to the standard. The device also features 6 kO of transimpedance gain and incorporates a linear photo current monitor, on chip photodiode filter and extended temperature range operation of –40° C to +105° C.

Standards Compliant Rate Selection
The VSC7964 and VSC7977 is the only available chipset to offer bandwidth adjustment to meet the 4 Gbps INCITS/T11 Fibre Channel standards. Through the rate select control input on the VSC7964, the bandwidth of both the post amplifier and TIA functions can be adjusted to one of four settings, maximizing the performance at the configured data rate and ensuring backward compatibility with the legacy technology currently deployed. This bandwidth selection capability provides module manufactures with up to 2.5 dBm of additional receiver sensitivity at 1G data rates.

Enhanced Digital Diagnostics
The VSC7964 has been designed to seamlessly operate with a standard microcontroller to provide the required SFP/SFF-8472 Digital Diagnostic capabilities, thereby providing the SFP designer greater functionality and flexibility than specialized digital diagnostics chip solutions. By communicating digitally through the use of integrated DACs and a Serial Peripheral Interface (SPI), the designer has complete access to the VSC7964 registers, such as the laser bias, modulation and peaking currents, and the LOS threshold settings, thus maximizing implementation flexibility and increasing the testability. This enhanced functionality can be used to reduce the calibration and test time, while enabling module manufactures to differentiate themselves by offering advanced diagnostic and management features not available when using a digital diagnostics chip-based solution.

8 Gbps Performance
Although the 8G Fibre Channel standard will not be completed until late 2005 or early 2006, indications are that the SFP form factor will be the module of choice. The power requirement and cost target will be similar to the 4G solution. Vitesse has already measured the VSC7964 performance at 8.5G. Link performance at 850 nm was verified over 180 meters of 50 µm multimode fiber that was compliant to the FC-PI-2 standard. This is a major step in confirming feasibility for the SFP form factor to support higher data rates.

Packaging, Pricing, and Availability
The VSC7964 Laser Driver/Post Amplifier is sampling now and is available in a 40-pin, 6 mm x 6 mm QFP-N package. Samples of the VSC7977 will be available in September 2004 and will be sold in die form or as a complete optical receiver in a standard 5-pin TO-46 package with a short wave PIN detector. The VSC7964YK and VSC7977-W laser driver, post amplifier, and TIA chipset is priced at $3.78 USD in production quantities.

About the Transport Products Division
Since introduction of the first SONET SerDes ICs nearly 15 years ago, the Transport Products Division at Vitesse has been a leading supplier of optoelectronics and physical layer devices for OEMs around the globe. With emphasis on the development of products to lower the cost of bandwidth for applications from 1 Gbps to 12.5 Gbps, Vitesse offers the industry’s broadest product portfolio.

As the world leader in transport ICs, Vitesse components are used in a wide array of products from industry leading OEMs including Alcatel, Avanex, Bookham Technology, Cisco, Huawei, Infineon, JDS Uniphase, Lucent, Marconi, Nortel, Opnext, and many others.

Vitesse is a registered trademark in the United States and/or other jurisdictions of Vitesse Semiconductor Corporation.

About Vitesse
Vitesse designs, develops, and markets a diverse portfolio of high-performance, cost-competitive semiconductor solutions for communications and storage networks worldwide. Engineering excellence and dedicated customer service distinguish Vitesse as an industry leader in Gigabit Ethernet LAN, Ethernet-over-SONET, Advanced Switching, Fibre Channel, Serial Attached SCSI, Optical Transport, and other applications. Vitesse innovation empowers customers to deliver superior products for Enterprise, Access, Metro, and Core applications. Additional company and product information is available at

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