How should I route differential signals on a printed circuit board (PCB)? - How should I route differential signals on a printed circuit board (PCB)? Description Use the following guidelines to route differential signals on a PCB. You can route the differential pair on the same layer (edge coupling) with minimal spacing between them (about 5 mils) or you can route the differential pair on two adjacent layers (broadside coupling). Regardless of how they are routed, the differential impedance must be 100 Ω. Even though the individual lines are 50 Ω, this does not mean the differential impedance will be exactly 100 Ω due to coupling, so the PCB designer must account for this. The signal route should not have any sharp turns. The length of both the positive and negative traces must be equal. The signal route should not pass through many vias, since a via represents an impedance discontinuity. The signal route should not cross any ground/power plane discontinuities. If the spacing between the negative and positive traces is S mils, then any other single-ended/differential line must be at least 3 × S mils away. Refer to AN 75: High-Speed Board Designs for more information. Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['novalue'] novalue novalue ['Programmable Logic Devices', 'Stratix® GX FPGA'] ['novalue'] ['novalue'] ['novalue']