Design007 Magazine


Issue link:

Contents of this Issue


Page 55 of 68

56 The PCB Design Magazine • March 2014 beyond design • A trace routed on the inner stripline layer exhibits 4–10 dB less noise then a trace routed on the outer, microstrip layer. • Microstrip layers are those that are fabri- cated on the outside of the substrate, top and bottom. The trace has a dielectric material on either side—FR-4 below and air above. • Microstrip traces are usually faster than stripline traces. • Stripline traces are totally embedded in di- electric material between planes. • The propagation delay of a serpentine trace is less than the delay through an equiva- lent length straight trace. The signal is sped up because a portion of the signal will propagate perpendicular to the serpentine. • If two traces of equal length are reference to different planes then the return paths may be considerable different and add round-trip delay. • Although two signals are exactly the same length, they may exhibit different delays. PCBDESIGN References 1. Barry Olney, Beyond Design: Impedance Matching: Terminations, Skewed Again, A New Slant on Matched-Length Routing, Differential Pair Routing, Embedded Signal Routing 2. Howard Johnson: High-Speed Digital De- sign 3. The ICD Stackup Planner and PDN Plan- ner: Barry olney is managing di- rector of in-Circuit Design Pty ltd (iCD), Australia. This PCB design service bureau special- izes in board-level simulation, and has developed the iCD stackup Planner and iCD PDn Planner software. To read past columns, or to contact olney, click here. CliCk To View Video Interview Dr. Michael steinberger discusses a few of the papers he is presenting or co-wrote for DesignCon. steinberger's papers always generate a great response at DesignCon, year after year. Steinberger Papers A Big Hit by Real Time with... PCBDesign007 Matched Length Matched Delay continues

Articles in this issue

Links on this page

Archives of this issue

view archives of Design007 Magazine - PCBD-Mar2014