Agilent 5990-9784EN Tips and Techniques for Accurate Characterization of 28 Gb s Designs - Application Note free download

File name 5990-9784EN Tips and Techniques for Accurate Characterization of 28 Gb s Designs - Application Note

Keysight Technologies Tips and Techniques for Accurate Characterization of 28 Gb/s Designs Application Note Introduction The worldwide demand for data Measurement Challenges capacity in networks greatly increases every year, driven by services like cloud Lower jitter budgets. High measurement computing and Video on Demand. As installed networks approach their As rates increase, the bit periods idelity required. capacity, operators need to either become shorter. With shorter bit To ensure the signal is accurately add physical capacity, which is very periods, the jitter must be lower represented by the oscilloscope, high expensive, or transfer more data than ever before, even to the sub- data rate applications require more through the existing networks. These picosecond range. To ensure accurate measurement bandwidth, lower noise factors drive the need for much higher transmitter characterization, the and minimization of delays between data rates, and the medium and intrinsic jitter of test equipment must trigger and data stream. long haul transmission is handled by be significantly less than the specified fiber optic networks. Data is initially transmitter jitter. Analyzing closed eyes. and finally handled within electrical circuits, and is limited to relatively After high speed signals have passed Clock recovery required. through a backplane or similar lossy short distances primarily because of the loss in electrical channels. Within While sampling oscilloscopes are channel, the inter-symbol interference a few short years, the challenges known for their high measurement (ISI) that is introduced may close the of developing solutions that handle accuracy, they require a synchronous eye entirely. Innovative measurement 10 Gb/s have faded and have been clock as a trigger. Often there is techniques allow the user to replaced with new challenges at rates no access to a suitable clock, or re-open the eye and characterize the of 14 Gb/s to 120 Gb/s, resulting in a clock recovery must be utilized for parameters. proliferation of multi-channel standards compliance reasons, and hardware and applications. clock recovery must be employed. Keysight Technologies, Inc. continues to anticipate and provide innovative test solutions as designers move through early development and validation cycles. This application note focuses on test solutions for electrical transmitters operating from