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I'm looking through USB 3.1 specs and can't find any answer about one simple question.

I'm designing USB Type C to USB 3.0 Female A adapter, which will require USB 3.0 bandwidth (5Gbps) and standard 3.0 supply (900mA@5V). The idea i can't determine - can it be done without special ICs (like TUSB321 or CCG1/2)?

What i'm thinking for now: it can't be done without something like TUSB321 (which determines necessary current through CC). If i'm wrong - i'll be glad to hear it.

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The wiring for what I believe you are describing is in the USB Type-C document, section 3.6. Link to that document: https://www.usb.org/sites/default/files/USB%20Type-C%20Spec%20R2.0%20-%20August%202019.pdf

If that is not the wiring diagram you are looking for then it may be because you are thinking of a cable or adapter not allowed by the USB specifications. The allowed cables and adapters are in section 2.2 of that document.

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  • \$\begingroup\$ Thank you for your response! This question originates from 2015, and I'm afraid I do not even recall how this project ended. But now, I indeed know the correct answer - described adapter will require at least two ICs (or a single combined): configuration logic (the one which handles CCx pins) + high-speed mux (for supporting type c cable rotation) \$\endgroup\$
    – Looongcat
    Commented Nov 30, 2021 at 7:44
  • \$\begingroup\$ Right, this is an old question. I have a habit of not noticing the date. I'm pleased to know someone found my answer helpful. \$\endgroup\$
    – MacGuffin
    Commented Nov 30, 2021 at 7:54
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Yes all you need in this case is a Rd( Pull down resistor) across CC line.

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    \$\begingroup\$ Some links to relevant specifications or example circuits would improve this answer. \$\endgroup\$
    – David
    Commented Oct 26, 2015 at 20:29
  • \$\begingroup\$ You can refer USB Type-CTM Cable and Connector Specification Revision 1.1, April 3, 2015 from usb.org/developers/docs/usb_31_102015.zip Also you can refer simplified gist of the specification and other details in amazon.com/gp/product/B014SO7U4W \$\endgroup\$
    – RERA
    Commented Oct 27, 2015 at 4:43
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USB C to USB A adapter at 5Gbps is quite simple. As described in page 77 of above document:

connection diagram

The USB C Host will drive the correct lane I guess. Example connection

Source:From Infenion site

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