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Electronics => Beginners => Topic started by: JustAnotherGuy999 on February 25, 2016, 07:24:21 pm

Title: Visualising USB 2 High Speed (480 Mbit/s) on an oscilloscope
Post by: JustAnotherGuy999 on February 25, 2016, 07:24:21 pm

What is the minimum specification (bandwidth, sample rate,memory depth, number of channels) of an oscilloscope to visualize USB 2 High Speed Signals.
PS: i posted this question on many forums, and i either got blocked, or i don't get an answer.
Is there an international law preventing people from visualizing USB 2 High Speed signals on oscilloscopes?
its just usb 2 not usb 3, come on

Title: Re: Visualising USB 2 High Speed (480 Mbit/s) on an oscilloscope
Post by: marshallh on February 25, 2016, 07:46:57 pm

at least 2-4x the bandwidth (0.48gbps) so 1ghz to even see the signaling, 2ghz or 4ghz preferred.

Title: Re: Visualising USB 2 High Speed (480 Mbit/s) on an oscilloscope
Post by: JustAnotherGuy999 on February 25, 2016, 07:55:11 pm

thanks

Title: Re: Visualising USB 2 High Speed (480 Mbit/s) on an oscilloscope
Post by: free_electron on February 25, 2016, 08:25:26 pm

1ghz bandwidth, 4gs/s and deep memory. and get a machine that can run protocol analysis.

Title: Re: Visualising USB 2 High Speed (480 Mbit/s) on an oscilloscope
Post by: Jeroen3 on February 25, 2016, 08:33:27 pm

An "if you have to ask the price, you cannot afford it"-grade oscilloscope.
USB is differential, so either a diff probe, or a math channel. A protocol analyzer that is able to trigger would be helpful too.

Maybe try renting the equipment.

Title: Re: Visualising USB 2 High Speed (480 Mbit/s) on an oscilloscope
Post by: John_ITIC on February 25, 2016, 10:47:17 pm

Do you want to visualize the analog voltage or the packets sent on the link? For the latter, you'll need a USB protocol analyzer. I design and sell such units.

Title: Re: Visualising USB 2 High Speed (480 Mbit/s) on an oscilloscope
Post by: JustAnotherGuy999 on February 25, 2016, 11:01:10 pm

Yeah i want to visualize the analog voltage

Title: Re: Visualising USB 2 High Speed (480 Mbit/s) on an oscilloscope
Post by: gslick on February 27, 2016, 01:33:04 am

USB electrical specification compliance testing is probably much more involved than what you are looking to do, but you still might find some useful information in some of the compliance test procedure documents available here for some of the major test equipment manufacturers:

http://www.usb.org/developers/compliance/electrical_tests/ (http://www.usb.org/developers/compliance/electrical_tests/)