If I understood correctly, when designing PCB with USB, the 90-ohm differential pair of D+/D- trace if for matching the USB cable differential impedance. Otherwise, there will be a signal reflection where the impedance is not continuous.
For those USB devices WITHOUT cable, for example,
- USB storage
- Wi-Fi module with USB interface, like this
Is it still necessary to trace D+/D- as 90-ohm differential pair?