PCB Crosstalk Calculator
Estimate crosstalk between parallel traces
Input Parameters
Aggressor
S=5mil
Victim
W=5mil
H=4mil
Ground Plane
Results
poor Isolation
Consider increasing spacing or using guard traces
Near-End (NEXT)
9.10%
-20.7 dB
Far-End (FEXT)
6.07%
-24.2 dB
S/H Ratio
1.25
⚠ Low
3W Rule
FAIL
Need S ≥ 15 mil
For 3W rule compliance, increase spacing to at least 15 mil
Design Rules
- 3W Rule: Space traces ≥3× width for <3% crosstalk
- S/H > 2: Spacing should be 2× dielectric height
- Minimize parallel length where possible
Mitigation Techniques
- • Increase trace spacing
- • Route on different layers
- • Use guard traces with vias
- • Reduce parallel routing length
- • Route at 90° angles when crossing