Length matching for parallel buses in PCB Design - Dashboard Guide

Dashboard Mode - Length matching for parallel buses

Goal

Understand how length matching affects signal timing in parallel buses on a PCB and identify which bus lines need adjustment.

Sample Data: Bus Line Lengths and Delays

Bus Line	Length (mm)	Signal Delay (ns)
Line A	100	0.5
Line B	102	0.51
Line C	98	0.49
Line D	100	0.5
Line E	105	0.525

Dashboard Components

• KPI Card: Max Length Difference
  Formula: MAX(Length) - MIN(Length) = 105 - 98 = 7 mm
• Bar Chart: Bus Line Lengths
  Shows each line's length in mm for visual comparison.
• Table: Lines Needing Adjustment
  Filter lines where length difference from shortest line > 2 mm.
  Lines: B (4 mm diff), E (7 mm diff)
• Line Chart: Signal Delay vs Length
  Plots length on X-axis and delay on Y-axis to show correlation.

Dashboard Layout

+----------------------+----------------------+
|      KPI Card        |     Bar Chart        |
|  Max Length Diff     |  Bus Line Lengths    |
+----------------------+----------------------+
|    Table: Lines      |   Line Chart: Delay  |
|  Needing Adjustment  |   vs Length          |
+----------------------+----------------------+

Interactivity

Filter by length difference threshold (e.g., > 2 mm) updates the table and highlights bars in the bar chart. Selecting a bus line in the table highlights its point in the line chart and bar chart.

Self Check

If you set the length difference filter to > 5 mm, which lines remain in the table? (Answer: Only Line E)

Key Result

Dashboard shows bus line lengths, signal delays, and highlights lines needing length adjustment for timing alignment.