National Semiconductor Introduces Jitter SerDes Chipset

Santa Clara, CA - A new serializer and deserializer (SerDes) chipset from National Semiconductor Corp. delivers the industry's best output jitter performance of 35 ps peak-to-peak and the best input jitter tolerance of 0.9 units interval (UI) with a bit error rate (BER) of 10 (-15). The SerDes chipset serializes data up to 3.125 Gbps and is well-suited for industrial and medical imaging, communications infrastructure, commercial displays, and test and measurement systems.

The highly integrated chipset includes the DS32ELX0421 serializer and DS32ELX0124 deserializer. They feature advanced on-chip signal and clock conditioning circuitry that extends data transmission reach of CAT-6 (shielded 23 AWG) cable beyond 20 meters. The SerDes also support a wide variety of interconnect media, including CAT-5 cable, optical fiber, 50-Ohm or 75-Ohm coaxial cable and FR-4 backplanes.

The SerDes' unique architecture replaces the traditional wide single-ended parallel bus with a 5-bit low-voltage differential signaling (LVDS) interface. This breakthrough interface simplifies board layout by reducing the number of input/output (I/O) pins and traces between the serializer, deserializer and field-programmable gate array (FPGA). In addition, the SerDes' LVDS interface reduces electromagnetic interference (EMI), while enabling the use of low-cost FPGAs in a variety of high-speed, high-performance applications.

The SerDes' redundant I/Os and retimed active loop-through enable advanced system configurations such as failover, link aggregation and daisy chaining. Power consumption is less than 1W, and both devices include an automatic standby mode using signal detect and a configurable sleep mode for additional power savings.

"National's new family of high-speed serializers and deserializers is optimized to serve as a front-end chipset to our low-cost Spartan-3 Generation FPGA products," said Oliver Garreau, senior engineering manager in the Spartan FPGA Group at Xilinx. "This SerDes solution supports a broad array of high-speed applications with excellent analog performance, while remaining cost-effective thanks to a high level of integration."

"Low cost FPGA families have lacked the ability to support high speed serial interfaces," said Jim Beneke, vice president of global technical marketing for Avnet Electronics Marketing. "With the introduction of National Semiconductor's new serializers and deserializers, our customers now have the ability to add high speed serial interfaces that are both easy to implement and cost effective. Together National and Avnet have developed the necessary tools and reference designs to help our FPGA customers succeed in using these exciting new SerDes products."

National also offers reference IP and design guides for interfacing FPGAs to the DS32ELX0421 and DS32ELX0124. As part of its FPGA IP package, National includes a bit error rate test (BERT) engine for test pattern generation/validation and system-level functions such as link aggregation and failover.

Technical Features - DS32ELX0421 Serializer

Offered in a small 48-pin LLP package, National's DS32ELX0421 serializer includes a double data-rate (DDR) 5-bit LVDS parallel data interface and a redundant serial output channel. The integrated jitter cleaning PLL accepts a wide 125 MHz to 312.5 MHz input clock for a serial data rate of 1.25 Gbps to 3.125 Gbps. The DS32ELX0421 allows programming of transmit de-emphasis levels, output voltage levels, and selection of DC-balance encoding. This programming flexibility enables the use of DS32ELX0421 in a wider range of interconnect media and applications compared to existing serializers. A remote sensing feature automatically detects and negotiates link status with the companion DS32ELX0124 deserializer. The DS32ELX0421 typically consumes 470 mW of power at 3.125 Gbps.

Technical Features - DS32ELX0124 Deserializer

Offered in a small 48-pin LLP package, National's DS32ELX0124 deserializer includes a DDR 5-bit LVDS parallel interface, redundant serial input and retimed serial output channel. The DS32ELX0124 deserializes up to 3.125 Gbps of high-speed serial data to five LVDS outputs without the need for an external reference clock. The DS32ELX0124 offers programmable receive equalization, and a minimum jitter tolerance of 0.9 UI. A remote sensing feature automatically signals link status conditions to its companion DS32ELX0421 serializer for intelligent link management. The DS32ELX0124 typically consumes 525 mW of power at 3.125 Gbps.

In addition to the DS32ELX0421 serializer and DS32ELX0124 deserializer, National also offers the DS32EL0421 serializer for applications that do not require a redundant serial output channel and the DS32EL0124 deserializer without a redundant serial input and a retimed serial output channel.

About National's Interface Portfolio
National Semiconductor, the LVDS and CML technology innovator and market leader, offers a wide range of interconnect solutions that transfer high-speed digital signals using world-class analog technology. These solutions help system designers develop high-performance applications in a variety of markets, including communication and industrial systems. The products feature high reliability, low power and low noise, as well as dramatic systems savings in cable and connector costs. National Semiconductor is the world's largest supplier of high-speed LVDS products, according to Databean's 2007 Analog IC Market Share survey. For more information on National's interface products, visit http://www.national.com/appinfo/interface/.

SOURCE: National Semiconductor Corp.