Oscilloscopes Ramp Up
When I was in high school, the physics teacher brought out the Dumont oscilloscope whenever it came time to discuss electricity. I don't recall its model number, and the demise of Dumont is ancient history. But with its formidable set of knobs clustered around the 5-in. CRT, it certainly appeared state-of-the-art to us tyros.
How far oscilloscope technology has come since then! CRT technology was the basic building block in oscilloscope innovation. It too has come far since its inception over a century ago. Driven by the need for radar in the '30s prior to World War II, CRT technology advanced to the point where it played a crucial role in the outcome of that war. Once peace returned in 1945, the CRT was ready to assume its place in the oscilloscope. It's still holding its own despite the onset of flat-panel displays.
Driven by demands for bandwidth and climbing data rates over the past half-century, the oscilloscope spawned digital scopes, sampling scopes, logic analyzers, and protocol analyzers. To do all of this, it has received major assistance from advances in silicon technology, the PC, and digital-signal processing.
Look for more specialized analysis packages. Because of the increasing complexity of system tests and time constraints, scopes are no longer primary measurement instruments. They are sophisticated analysis devices. A prime example is mask testing. Users will increasingly be able to program in added test procedures as new industry standards are approved. Also to be introduced are more specialized triggering packages, such as the serial pattern trigger just recently announced. It enables engineers to program a certain sequence of bits and trigger on that.
Probing is becoming more difficult, although help is on the way. The problem is primarily due to the continued shrinking of products and packaging, the advent of SMT packaging, and flip chips, which all make it increasingly difficult to place a probe on exactly the right node. Look soon for announcements of innovative probing techniques that will surmount these difficulties.
Engineers will probably always require a sampling oscilloscope as a lab instrument and as a reference point. But they like to work with real-time oscilloscopes. Clock rates in real-time scopes will continue climbing, driven in part by the climb in data rates, as will bandwidths, now in the vicinity of 4 GHz.
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