Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
EE Times-Asia > Amplifiers/Converters

3Gbps Serdes touts lowest output jitter of 50ps

Posted: 22 Jun 2007 ?? ?Print Version ?Bookmark and Share

Keywords:discrete SDI Serdes? serial digital interface? 65nm?

National Semiconductor has introduced a 3Gbps multirate serial digital interface (SDI) Serdes to complement National's expanding portfolio of professional and broadcast video products.

Leveraging the company's analog expertise, National's engineers achieved a breakthrough in performance to enable the industry's lowest output jitter SDI serialiser (50ps) and highest input jitter tolerance deserialiser (0.6 units interval). Moreover, the 3Gbps chipset revolutionizes the way professional video system designers interface SDI Serdes with host FPGAs. National also introduced a separate 3G SDI chipset, including equalizer, reclocker and cable driver.

Integrated components
The chipset consists of the LMH0340 3G serialiser with integrated cable driver and LMH0341 deserialiser with reclocked serial loop-through. The products provide 3Gbps transmit and receive functions for a wide range of broadcast video production and processing applications, including production switchers, digital video recorders, camcorders, video format converters and video editing equipment. The chipset is the first discrete SDI Serdes to support the new Society of Motion Picture and Television Engineers (SMPTE) 424M specification for uncompressed serial transmission of 1,080p high-definition (HD) broadcast video signals up to 60fps.

The chipset's architecture uses a proprietary technique to reduce the parallel bus between the serialiser and FPGA from a 20bit single-ended interface to a 5bit LVDS interface. This simplifies board layout by reducing the number of traces between the serialiser, deserialiser and FPGA. Moreover, the chipset's LVDS reduces EMI, while the narrow parallel bus enables a single low-cost FPGA to support a greater number of high-speed video channels.

"National's SDI Serdes combined with the first 65nm, low-cost FPGAs, provide a compelling triple-rate SDI solution for broadcast equipment manufacturers," said Todd Scott, senior director of Altera's broadcast business unit. "System designers can now take advantage of the increased video quality of 1080p on the just-announced Cyclone III FPGA family in addition to the Serdes integrated Stratix IIGX family."

"We're delighted to collaborate on the LMH0340/341 Spartan-3E-based evaluation platform," said Paolo Masini, senior manager of Broadcast Vertical Marketing at Xilinx. "National's new family of SDI serialisers and deserialisers are the perfect complement to our Spartan-3E family of FPGAs. This combination offers a very high performance and competitively priced solution for high speed broadcast connectivity requirements."

National claims to be the only analog semiconductor supplier to offer a complete portfolio of products for 3Gbps SDI applications, including serialiser (LMH0340), deserialiser (LMH0341), equaliser (LMH0344), reclocker (LMH0346) and cable driver (LMH0302). All National 3G SDI products have pin-compatible HD versions, allowing designers to complete a single design and populate boards according to the required maximum data rate standard, such as SD, HD or 3Gbps.

HD/SD serialiser/driver
Offered in a small 48-pin LLP package, National's LMH0340 3Gbps multirate SDI serialiser supports 270Mbps, 1.485Gbps and 2.97Gbps data rates, enabling transmission of DVB-ASI, standard-definition (SMPTE 259M), high-definition (SMPTE 292M) and the new 3Gbps SDI standard (SMPTE 424M) for uncompressed serial transmission of 1,080p50/60 signals over a single link of coaxial cable.

The integrated SMPTE-compliant cable driver reduces system chip count, conserves board area and lowers power consumption. At 3Gbps and HD rates, it delivers the industry's lowest output jitter of 50ps, without the use of an external voltage-controlled oscillator (VCO). The serialiser and driver consume 437mW of power from typical supply voltages, delivering a 40 percent power reduction over existing HD solutions requiring a serialiser and external driver.

HD/SD reclocking deserialiser
Offered in a small 48-pin LLP package about 60 percent smaller than competitive HD products, National's LMH0341 is the companion deserialiser to the LMH0340 supporting DVB-ASI at 270Mbps and SDI for SD, HD and 3Gbps data rates. LMH0341 features an integrated reclocker that provides a wide input jitter tolerance of 0.6 unit intervals (UI), allowing the product to receive and deserialise signals with more than 60 percent of the signal's "eye" closed. The reclocked loop-through feature includes an integrated cable driver that automatically adjusts the output slew rate compliant to the incoming data rate. Similar to the LMH0340, it requires no external VCO. At 2.97Gbps, typical power consumption is 445mW, approximately half that of competitive devices operating at HD rates.

In addition to National's chipset for 3Gbps multirate operation, the company also offers two chipsets for HD/SD operation and one for SD-only operation. These chipsets include the LMH0040 serialiser and LMH0041 deserialiser for full-featured HD/SD operation, LMH0050 and LMH0051 for reduced cost HD/SD operation, and the LMH0070 and LMH0071 for SD-only operation.

- Henri Arnold
EE Times Europe

Article Comments - 3Gbps Serdes touts lowest output jit...
*? You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.

Back to Top