Optimized Board Layout Solution
Stratix® II GX is the only FPGA with embedded transceivers capable of supporting a data rate of up to 6.375 Gbps on twenty channels simultaneously, meeting the bandwidth requirement of today’s leading edge applications. As data rates increase, the challenge to board designers also increases. For example, Stratix II GX transceivers are capable of supporting twice the speed of the previous generation of devices, however as data rates double, board losses increase by over five times. This increases the complexity of board design and increases the level of design effort involved.
Board designers must be equipped with enhanced circuitry within the transceiver, coupled with a complete set of tools and collateral in order to achieve an optimized layout. The Stratix II GX board solution combines the robust architecture of the Stratix II GX transceiver with a suite of development boards, tools, and collateral to reduce PCB design time and increase the likelihood of a successful board layout the first time without any compromise to data link performance.
Transceiver Architecture
Stratix II GX transceivers successfully operate at maximum data rates on transmission lines in excess of 40" (1.25 M) in length, on standard FR-4 PCB material. To achieve this, the transceivers provide excellent jitter performance and robust noise immunity. The transceivers also provide a number of features to ensure signal integrity at these higher data rates, including:
Power Optimized Transceiver
The Stratix II GX transceiver circuitry is optimized to keep power requirements low without compromising performance to the transceiver. Stratix II GX transceivers require around 140 mW per channel at 3.125 Gbps and around 200 mW per channel at 6.375 Gbps. On average, the Stratix II GX transceivers require less than half the power of the nearest competitor. Figure 1 shows a comparison between the Stratix II GX transceiver power consumption and the nearest competitive solution. Figures are taken from the competitors data sheet and from Stratix II GX characterization.
Figure 1. Transceiver Power Comparison
In addition, the robust transceiver circuitry of the Stratix II GX FPGA requires significantly fewer external power supply components than competing transceiver-based FPGA solutions, leading to simplified board layout and lower overall system costs.
Figure 2 shows the simplified board layout for the Stratix II GX PCI Express Board.
Figure 2. Stratix II GX PCI Express Board
For more details, visit the Stratix II GX Transceiver Power Page.
Signal Integrity Development Kit
A Signal Integrity Development Kit has been created for Stratix II GX devices to support signal integrity engineers during the transceiver appraisal process and to provide board design engineers with a basis for PCB reference design. The board includes complete layout information, layout guidelines, and Gerber files.
The Signal Integrity Development Kit–Stratix II GX Edition includes a training tutorial that provides insights into the design of high-speed serial links from Dr. Eric Bogatin, an industry leading expert on signal integrity.
Collateral and Tools
It is extremely important to understand a board’s characteristics to produce a successful rollout. Stratix II GX board solutions deliver a complete set of collateral and tools to enable engineers to model their PCB layout and to select the correct transceiver signal integrity configuration to ensure success. Tools include:
|
Literature
> 
