Linux USB - more information on what matching circuit is required

Go to previous topic

Go to next topic

Last Post 24 Oct 2013 04:31 PM by steven.eckhoff

3 Replies

Author

Messages

steven.eckhoff

Basic Member
Posts:192

17 Oct 2013 10:42 AM
Hi, In document PN 1020541 Rev 5 section 4.8 it states that "In order to correctly implement USB on the DM3730 Torpedo + Wireless SOM, additional impedance matching circuitry may be required on the USB1_D+ and USB1_D- signals before they can be used." Do you have any more information on what matching circuit is required? Thanks for your help Matt

steven.eckhoff

Basic Member
Posts:192

18 Oct 2013 10:31 AM
Additional information is contained in the USB 2.0 specification[1]. You can also use our Launcher 3 schematics [2] for a reference. [1] http://www.usb.org/develo...cs/usb_20_070113.zip [2] http://support.logicpd.co...id=0&EntryId=589

Matt Sacker

New Member
Posts:4

21 Oct 2013 11:40 AM
Hi Steven, I have checked your reference schematics and I cannot find any matching components on the USB bus from the Torpedo module. Am I missing something? Thanks for your help Matt

steven.eckhoff

Basic Member
Posts:192

24 Oct 2013 04:31 PM
Matt, I cannot provide any further information without looking at your design. Take a look at the USB spec that I included to get an idea of the impedance matching required for your board. On the Launcher 3 baseboard no extra components were added, but in general it serves as a starting reference design. We offer higher levels of design support, which would allow us to look into your requirements more closely. If you are interested in this I can have someone contact you.