11.1 Layout Guidelines

For the trace routing of DP_IN, DM_IN, DP_OUT, and DM_OUT: route these traces as micro-strips with nominal differential impedance of 90 Ω. Minimize the use of vias in the high-speed data lines. Keep the reference GND plane devoid from cuts or splits above the differential pairs to prevent impedance discontinuities. For more information, see the High-Speed USB Platform Design Guidelines from Intel.

The trace routing from the upstream regulator to the TPS2547 IN pin must be as short as possible to reduce voltage drop and parasitic inductance.

In order to meet IEC61000-4-2 level 4 ESD, external circuitry is required. Refer to the guidelines provided in the 相关文档 section.

The traces routing from the RILIM_HI and RILIM_LO resistors to the device must be as short as possible to reduce parasitic effects on the current-limit accuracy.

The thermal pad must be directly connected to the PCB ground plane using wide and short copper trace.

11.2 Layout Example

Figure 46. Layout Recommendation