Via
capacitance is calculated as:
Where,
-
- Diameter of clearance hole in the ground plane [cm]
-
- Diameter of pad surrounding via [cm]
-
- Thickness of PCB [cm]
-
- Relative electric permeability of PCB material
-
- Parasitic via capacitance [pF]
Consider a signal coming from back side of the board to the topside of the board
through a via.
= 0.157 cm thickness board,
= 0.071 cm,
= 0.127 cm.
= 0.51pF