Impedance

This item analyzes and checks single-ended and differential impedance of target nets.

This item checks the followings:
  • Check the single-ended impedance.
  • Check the differential impedance (Characteristic, Zdiff, Zcommon).
    Figure 1.


  • Item: Enter sub item name. User can enter arbitrary name.
  • Net Group: Select target net groups to be tested. Allow multiple net groups.
  • Target Impedance: You can assign required impedance for main area and break in area. You can also set tolerance (%) for each main area and break in area.
    Figure 2.


    Figure 3. Break-In/Out Definition


  • Options: You can assign PIN/VIA Escape length and other options.
  • Pin Escape: Enter a radius of circular region around pins to be excluded for the rule check.
  • Via Escape: Enter a radius of circular region around vias to be excluded for the rule check.
  • Ignore trace shorter than: the trace shorter than this length will be ignored.
  • Break-In range (COC+distance): Enter Break-In range value. The break-in range refers to the sum of the distance within the COC line and the user defined distance outside of COC line.
    Figure 4.


  • Ideal: Consider the reference plane as ideal plane during analysis. If this option is used, the reference is determined using the settings of the PCB stackup.
  • Real: Analysis proceed by reflecting the shape of the reference plane. If this option is used, the net with net type "Ground" is regarded as the reference plane.