High-speed/RF digitizers tout 25-Gbit/s optical data streaming

Senior Technical Editor Alex Mendelsohn

eeProductCenter (04/06/2005 2:26 PM ET)

Monroe, New York— In the world of high-speed digitizers, Switzerland-based Acqiris has established a beachhead with its very high-speed data conversion instruments. The company continues this trend with these latest single-channel and dual-channel 6U-sized cPCI (CompactPCI) streamer analyzers.

Both plug-ins are quite new; although the company has shipped some of them, it is ramping up for production, and the datasheets haven't been finalized (we'll update this story when they are).

What makes these plug-ins especially noteworthy are their optical links. Both use what Acqiris refers to as ODLs, or optical data links. The ODL optical data transceiver is what endows these products with data streaming at rates as high as 25-Gbits/s!

Dedicated Silicon

The Model SC240 and Model SC210 streaming analyzers use the company's XLFidelity and JetSpeed analog-to-digital converter chipsets. These chipsets were designed for use with mass storage devices, or downstream post-processing engines.

In use, the XLFidelity chipset provides signal conditioning, amplification, and interleaving functions. The JetSpeed chipset not only provides clock and sync signals, but it also captures and stores acquired data. Both streamer analyzers are also equipped with on-board FPGA-based (field programmable gate array) data processing units. The DPU data handling blocks permit acquired data to be passed in its raw state, or with minimal DPU-implemented processing. This occurs through two optical ports. These ports are compliant with the SFPDP (Serial Front Panel Data Port) protocol. More on the FPGA-based DPU in a moment.

Ten Optical Data Links

A standard ODL offers two bi-directional optical links, each capable of simultaneously transmitting and receiving data at up to 2.5-Gbits/s, however an optional higher-rate ODL configuration offers a whopping ten bi-directional optical data links. This offers an aggregate throughput of up to 25-Gbits/s, or as multiple individual links, each at 2.5-Gbits/s.

Both streamer analyzer platforms also tout 1-GHz front-end bandwidths. The SC240, slated primarily for I/Q (in-phase and quadrature) acquisition, offers two synchronous channels, each with up to 1-Gsample/s sampling rate.

For single-channel applications, the two channels of the SC240 can be interleaved to get up to 2-Gsamples/s of sampling on either channel. That's software-selectable.

For its part, the SC210 offers a single input-channel that can sample at rates to 1-Gsample/s.

More High-Speed Features

Back to the streamer's DPUs. As mentioned above, they're based on Xilinx Virtex II Pro 70 FPGAs. These FPGAs are capable of executing multiplications in less than 5-ns. The engine also offers more than 74,000 logic cells, 328 dedicated 18-bit x 18-bit multipliers (with 36-bit results), and nearly 7-Mbits of on-chip processing memory.

Acqiris also offers an optional on-board processing memory extension for these products. It offers up to 512-Mbytes of DDR SDRAM, and 2-Mbytes of dual-port SRAM, ensuring a Read/Write throughput of up to 2 Gbytes/s to and from the FPGA.

Front-Panel Digital I/O

A DPU Control provides several front-panel digital I/O connectors. These give you extended realtime control of the DPU.

Two connectors (P1 and P2) are dedicated to direct control of the DPU. A third analog-output signal is derived from a 16-bit on-board digital-to-analog converter. This DAC output can be used in control systems, too.

For more advanced user-defined system control, both Acqiris platforms also offer an extended I/O port through a front-panel DB-15 connector. It provides up to seven bi-directional differential pairs for communication with the DPU.

Trigger and timebase control is also quite flexible. It's accomplished through four MMCX (micro-miniature RF connectors) connectors. These provide for the use of an external clock (up to 2-GHz for the SC240 and 1-GHz for the SC210). Alternatively, you can pipe-in an external 10-MHz reference clock.

The MMCX port also supports a trigger output, and two additional I/O digital control lines. These control lines can be used to monitor or modify platform status and configuration, or be used as a built-in 10-MHz source.

Combining Streamers

If your application requires more than two data-acq channels, several streamer analyzers can be combined using Acqiris's ASBus. It's a proprietary high-bandwidth auto-synchronous bus system.

The ASBus handles the distribution of all necessary trigger and clock signals for multi-channel applications. Since each ODL port is independent of the others, as well as of the host PCI bus, each additional streamer analyzer platform increases the total data throughput available.

So, if you're signal processing requirements include working with leading-edge applications such as electronic warfare, SIGINT/ELINT, radio astronomy, or perhaps synthetic aperture radar— or any applications requiring scalable realtime data sampling and storage—and you need data streaming, be sure to look into these products.

According to Acqiris general manager Klaas Vogel the price for a single-channel SC210 starts at about $24,000. The dual-channel SC240 is priced starting at about $29,000. Units ship in about six weeks after receipt of order.

For more details, contact Vogel at Acqiris USA, PO Box 2203, 234 Cromwell Hill Rd., Monroe, New York 10950-1430. Phone: 845-782-6544. Fax: 845-782-4745. E-mail: info@acqiris.com

Visit the company' Web site for related techncial information.

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