I have brougth this topic up again, because I have some doubts: people
usually say that it is mandatory to use a 4-layered boards with impedance
matching when you have a USB 2.0 circuit on board. But my question is: even
if I know that the circuit won´t reach 20Mbps tops (very far from 480Mbps of
USB 2.0) is it really mandatory to have a 4-layers board? And the impedance?
What if I make the trace as short as possible, from the connector to the IC?
Thanks
Thiago
