2.1.2 Incorrect Impedance

USB signal pair(s) are also controlled impedance. The impedance between the signals (differential) and the impedance between the signal and ground (single-ended) are specific values. The impedance on the circuit board must remain consistent to avoid unwanted reflections and other losses.

Tip: For best results, keep a constant, uninterrupted ground plane under the differential pair and avoid routing other signals near the pair. A wide range of free calculators can determine the required trace spacing from circuit board parameters.