TDR test traces

AN3317

18/22

Doc ID 18249 Rev 2

7

TDR test traces

Add test traces to all PCB designs on all signal layers.

It is simple to add a single trace of nominal impedance between 8 to 15 cm long on each

signal layer (it does not have to be straight) to all designs, and can it always be placed where

it will not impact the functional design, for example, usually along the board perimeter.

Include a test point pattern that matches your TDR probe. Test traces are invaluable in

validating PCB impedance parameters.

8

Layer order check

Include a visual feature (stair step numbered windows) to verify layer ordered in all PCB

layouts. This is most commonly located along one edge of the board.