About powered by UNIVERSAL SEREYAL BUS

Hai
Great Keil Forum Support Team.

How much currant could drive my USB port?
Kindly advice to avoid damaged for the usb port..if I'm not wrong the Voltage around 5 VDC and 4 VDC.

Regards
Jeckson

Parents
  • There is no single answer for your question. On initial start-up the USB port SUPPLIES 100mA. At enumeration, your descriptor file can request more current but the port supply depends on the number of devices and the current of the other devices.
    This is described in great detail in the USB specifications.
    Suggest that you search this forum for many additional USB posts and go to http://www.usb.org for complete specifications.
    Also, two excellent books are "USB Complete" by Jan Axelson (ISBN - 13 : 978-1-931448-02-4) and "USB Design by Examples" by John Hyde (ISBN 0-9702846-5-9).
    Bradford

Reply
  • There is no single answer for your question. On initial start-up the USB port SUPPLIES 100mA. At enumeration, your descriptor file can request more current but the port supply depends on the number of devices and the current of the other devices.
    This is described in great detail in the USB specifications.
    Suggest that you search this forum for many additional USB posts and go to http://www.usb.org for complete specifications.
    Also, two excellent books are "USB Complete" by Jan Axelson (ISBN - 13 : 978-1-931448-02-4) and "USB Design by Examples" by John Hyde (ISBN 0-9702846-5-9).
    Bradford

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