P2P R0 and Common Impedance – Complete Technical Explanation
1. P2P Resistance and R0 Inclusion
Point-to-Point (P2P) resistance includes all metal segments between two nodes.
Shared segment R0 may unintentionally be included, leading to overestimation.
Figure 1. Examples of P2P rules involving R0.
2. Common Impedance Concept
Figure 2. Definition of common impedance and its calculation.
Rcom = (Rab + Rac − Rbc) / 2
Rab = R0 + R1
Rac = R0 + R2
Rbc = R1 + R2
Rab + Rac − Rbc = 2R0 → Therefore Rcom = R0
3. Estimation of R0 from Common Impedance
Figure 3. Estimate of R0 based on the concept of common impedance:
R0 = (RAB + RAC − RBC) / 2.
Animated dots illustrate current flowing through shared segment R0
before splitting into independent branches.
Conclusion
Combining practical P2P extraction, common impedance formulation,
and animated current visualization provides clear understanding
of shared resistance R0 and its proper isolation.