Test And Measurement> Analyzers

There's no slowing logic analyzers, literally and figuratively. Numerous performance and ease-of-use advances are waiting. Yet with the emphasis shifting from parallel data buses to serial data buses with multigigabit-per-second throughputs, the venerable logic analyzer may seem to be an anachronism.

Not so, though, as evidenced by the steady stream of new, more powerful logic analyzers. While they were originally intended for debugging parallel logic, logic analyzers are still vital to the development of ultra-high-speed-bus hardware, even though many serial-bus data rates often exceed a logic analyzer's maximum word rate.

Despite the development of many protocol-specific analyzers, both types of instruments are in great demand by test engineers because they often complement one another. For early design debugging, capturing raw data, and system-level debugging, there's no substitute for the logic analyzer. Protocol analyzers, on the other hand, excel in debugging bus-related high-level software problems. These test tools feature deeper memories than logic analyzers and can configure triggering and filtering at a high level, without the need for the user to know bus-signal behavior.

The emergence of 2.5G and 3G wireless telephone networks is challenging T&M equipment manufacturers to deliver a new generation of test gear that can handle a vast amount of data traffic. A new generation of protocol analyzers is now emerging to help T&M engineers. These instruments feature sophisticated real-time hardware-assisted filters and triggers that minimize a protocol analyzer's influence on the validity of a signal's measurement.

Though present logic analyzers can't handle multigigabit-per-second serial data streams, future analyzers may be able to. Tektronix's TLA5000 and TLA7000 series logic analyzers, which incorporate the company's MagniVu technology and have up to 2 ksamples of memory per channel, can capture 2-Gbit/s data. But that still may not be fast enough for some of the higher-speed serial data buses. Nevertheless, higher-performance logic analyzers with wider bandwidths and more memory depths per channel should emerge with advances in IC hardware and software technologies.

Let's not forget, though, that spectrum analyzers with their great dynamic ranges and low distortion levels will continue to improve to satisfy broadband communications needs.

• MORE SOPHISTICATED SPECTRUM ANALYZERS for the rapidly growing cellular telecom market are anticipated. Agilent Technologies' PSA series for TD-SCDMA (time division-serial collision detection multiple access) and 1xEV-DV (1x evolution, data and voice) transmissions are just the beginning.
• A GROWING NUMBER OF PORTABLE ANALYZERS will meet the needs of burgeoning field applications. Instruments like Anritsu's powerful 3-GHz handheld Spectrum Master in a 4.9-lb case show that "portable" doesn't have to mean "less powerful."
• IMPROVED DATA ACQUISITION AND SAMPLING will be adopted by future logic analyzers for more precise measurements. Tektronix has shown the way with the MagniVu technology used in its TL5000 and TLA7000 series of logic analyzers.
• LOOK FOR MORE PROTOCOL-SPECIFIC ANALYZERS to hit the market. They will complement regular logic analyzers in analyzing and debugging bus data streams. Arriving on the scene will be instruments like the FCTracer from Computer Access Technology, which is designed for Fibre Channel communications.
• EXPECT ADVANCED JITTER ANALYSIS tools for high-speed serial buses. Agilent Technologies set the tone late last year with its 86100C Infiniium digital communications analyzer option. For the first time, it can provide accurate separate random and deterministic jitter analysis from 50 Mbits/s to 40 Gbits/s.
• RF SPECTRUM ANALYZERS covering bandwdiths of hundreds of gigahertz are on the way for high-frequency communications networks. Presently, analyzers like the 110-GHz R3172/3182 from Advantest America represent the state-of-the-art in such instrumentation.
• HIGH-PERFORMANCE VECTOR SPECTRUM ANALYZERS with wider bandwidths and deeper memories per channel will be needed for multicarrier power-amplifier testings, signal monitoring, and satellite measurements. Agilent Technologies' PSA-80BW with an 80-MHz demodulator and eight seconds of capture memory capability is a good example.
• EASIER-TO-USE FRONT-PANEL SOFTWARE-DRIVEN CONTROLS will continue to appear on the newest logic analyzers, creating faster learning curves for first-time analyzer users. Software improvements will give users access to an instrument's most common features through the push of a button or two. Pull-down menus and menu bars will become more common, making for more expedited testing and lower-cost development.
• HIGHER-SPEED SERIAL DATA ANALYZERS ARE ON THE WAY They'll be able to trigger on high-speed bit streams to more accurately measure jitter and channel-to-channel skewing on buses such as the PCI Express. The LeCroy SDA6000A/5000/3000A series of serial data analyzers can trigger on 2.7-Gbit/s data rates, double the rate available on many serial data analyzers available today.
• EXPECT TO SEE HIGH-PERFORMANCE LOGIC ANALYZER test probes that will complement more advanced logic-analyzer instruments as probe manufacturers work more closely with logic analyzer instrument manufacturers. This is an important development for high-speed serial buses like PCI Express. These probes are based on serializer/deserializer (SERDES) devices to interface a logic analyzer to the circuit under test. The probes will help by separating embedded clock information from the data that they capture.