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Last Post 24 Oct 2013 04:31 PM by  steven.eckhoff
Linux USB - more information on what matching circuit is required
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steven.eckhoff
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Posts:192


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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
    Basic Member
    Posts:192


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    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
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    Posts:4


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    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
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    Posts:192


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    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.
    You are not authorized to post a reply.

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