Enter the inductance and capacitance into the calculator to determine the impedance. This calculator can also evaluate any of the variables given the others are known.

Via Impedance Formula

The following formula is used to calculate the impedance in a via. 

Z = sqrt((L / C))

Variables:

  • Z is the impedance (Ohms)
  • L is the inductance (Henries)
  • C is the capacitance (Farads)

To calculate the impedance in a via, divide the inductance by the capacitance, then take the square root of the result.

What is a Via Impedance?

Via impedance is a measure of the opposition to the flow of electric current through a via, which is a hole in a printed circuit board (PCB) that allows electrical connection between different layers of the board. It is a critical parameter in high-speed digital and high-frequency analog circuits, as it can affect signal integrity, power integrity, and electromagnetic compatibility. The impedance of a via is determined by its physical dimensions, the dielectric constant of the PCB material, and the frequency of the signal passing through it.

How to Calculate Via Impedance?

The following steps outline how to calculate the Via Impedance using the formula: Z = sqrt((L / C)).

  1. First, determine the value of inductance (L) in Henries.
  2. Next, determine the value of capacitance (C) in Farads.
  3. Next, substitute the values of L and C into the formula Z = sqrt((L / C)).
  4. Finally, calculate the Via Impedance (Z) using the formula.
  5. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Inductance (L) = 5 Henries

Capacitance (C) = 10 Farads