1、 PAM4 measurements through lossy channels why oscilloscope CDR emulation matters Patrick Connally,Teledyne LeCroy Dhruv Gupta,Teledyne LeCroy Martin Miller,Teledyne LeCroy Lawrence Salant,Teledyne LeCroy Abstract The shift to PAM4-based signaling has introduced more complex figures of merit for tran
2、smitter characterization,such as signal-to-noise-and-distortion ratio(SNDR),as well as requirements for more sophisticated transmitter equalization(TxEQ)characterization.But higher-order modulation means increased impact of signal impairments on the robustness of methodologies to characterize device
3、s.At higher-loss channels,conventional clock-data recovery(CDR)emulation methods fail to function and become an impediment to these measurements.This paper examines why and shows practical effects using real-world SNDR and TxEQ measurements.These results compare conventional CDR methods to a highly
4、loss-tolerant CDR enabling measurement on highly lossy channels.Authors Biographies Dr.Patrick Connally has worked at Teledyne LeCroys oscilloscope division since 2013,where he is currently a product architect.His work involves product definition for high-bandwidth oscilloscopes,and signal analysis
5、methodologies for high-speed serial communications applications.He received his PhD from Queens University Belfast in 2006.Dhruv Gupta is a Computational Software Engineer at Teledyne LeCroy.As a part of the vertical market team,Dhruv helps develop the Serial Data Analysis package(SDAX),employed to
6、analyze high-speed standards such as PCIE,USB,and Ethernet.He received his Masters in Scientific Computing from the University of Pennsylvania and his Bachelors in Engineering Physics from IIT Hyderabad(India).Dr.Martin Miller received a doctorate in particle physics from the University of Rochester