signal integrity

PCB Differential Impedance

Calculate the differential impedance of a PCB trace pair.

Computes the differential impedance of a coupled PCB trace pair using: Zdiff = 2 × Z0 × (1 - 0.48 × e^(-0.96 × s/h)), where Z0 is the single-ended characteristic impedance, s is the spacing between traces, and h is the dielectric height.

Inputs

Characteristic Impedance(Ω)

Single-ended characteristic impedance of each trace in ohms

Space Between Traces(mm)

Edge-to-edge spacing between the two traces in millimetres

Height of Trace(mm)

Height of the dielectric substrate below the trace in millimetres

Results

⚠Height of trace must be greater than zero

Differential Impedance-ΩDifferential impedance of the trace pair in ohms