Agilent 5990-9250EN S-parameter Series Transforming Oscilloscope Acquisitions for De-Embedding 252C Embeddi free download

File name 5990-9250EN S-parameter Series_ Transforming Oscilloscope Acquisitions for De-Embedding_252C Embeddi

Keysight Technologies Transforming Oscilloscope Acquisitions for De-Embedding, Embedding and Simulating Channel Effects Application Note S-parameter Series Introduction to Signal Acquisition and Theory Realizing accu- This paper is the first of 6 papers whose intent is to guide designers and validation engineers of high- rate and reliable speed digital systems through the details of channel element measurement and modeling for the analysis of signal purpose of manipulating oscilloscope acquisitions to reveal the signals that the engineer wants to see data on today's and measure. This extra processing is required because the actual signal cannot be probed (for vari- high-speed digital ous reasons) or because the probed location is different than is desired, or because the measurement systems requires a elements themselves (i.e. probes) affect the measurement result and need to be removed from the thorough under- reported measurement. standing of the theories of analysis About ten years ago, the electronics industry departed from the traditional parallel bus interface and of data acquisi- embraced a serial topology. At first look this seemed a little strange. Not only did the bus clock rate tion. Armed with have to multiplied by at least a factor of 8 to get the same effective throughput, but it meant that an understanding digital designers would have to become expert at new blocks such as phase lock loops; tradition- of the theory, and ally an analog designers area. The issue at hand was that integrated circuit was becoming IO bound; knowledge of the it wasn't the internal capabilities but getting signals to and from the device. Additionally, the lowly tools, the designer printed circuit board made of FR-4 had become, in a sense, a precious commodity--in order to keep can accurately profit margins, the low cost material had to be used and running eight bit parallel buses was a waste and efficiently of routing real estate. The result of this technological departure was a headlong rush into higher data achieve precise rates and encumbent microwave principles applied in design. We now call this area of engineering, models of device Signal Integrity. behavior. This knowledge The problem that Signal Integrity practitioners address is the myriad of issues that come into play in allows the engineer the conveyance of digital data from a digital transmitter through a channel to a receiver. At billions of to develop bits per second (Gbs), everything in the transmission path affects the signal to some degree. De- optimum designs velopers and designers must learn what the most significant contributors are and how to model and the first time, measure them. When these are understood they can be entered into simulators or other measurement maximizing equipment