Is digital or Analog signal of USB 2.0 D+ & D- ?

[GoodMan]

Hi,

As title !


thanks a lot !

 

[joebazoka]

USB signals

Hi. In essence this signals are digital in a diferential configuration. In USB you have signals levels for different sates of the port. For example some levels are "disconnect", etc. You can find more information here:

https://www.beyondlogic.org/usbnutshell/usb2.htm

or in the usb standards. Regards.

 

[visualart]

It is the differential signal, need diffeent receiver and driver.
In usb1.1, it run aat 1.5MHz or 12MHz
in ysb20, ir tun at 280MHz

 

[xirix]

A simple question about USB 2.0: if I have to transmit only 20Mbps, I will see 20MHz with an oscilloscope?
If max speed is 480Mbps, this means 480 MHz on USB cable? Or the speed is constant and only payload varying inside USB packets?
The same question for USB 1.1

 

[visualart]

the speed is constant and only payload varying inside USB packets

 

[wpwang]

They are digital singal. You need control slop rate in spec.

 

[Memphis]

For my experience, both D+ and D- should be regard as the analog signals, and can be viewed as digital signals after the processing from the PHY (no matter UTMI in v2.0 or SIE in v1.1). FYI. :wink: