USB

[marce79]

Quanti volt trasmettono le porte USB?

[jordan air]

Se non ricordo male, trasmettono 5 volt...

[Andy94]

E' questo che cercate?

USB signals are transmitted on a twisted pair data cable with 90Ω ±15% impedance,[6] labeled D+ and D−. These collectively use half-duplex differential signaling to combat the effects of electromagnetic noise on longer lines. Transmitted signal levels are 0.0–0.3 volts for low and 2.8–3.6 volts for high in Full Speed (FS) and Low Speed (LS) modes, and -10–10 mV for low and 360–440 mV for high in High Speed (HS) mode. In FS mode the cable wires are not terminated, but the HS mode has termination of 45Ω to ground, or 90Ω differential to match the data cable impedance.