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AM1808 USB Pins Electrical Specffications

David Escandon
Expert 2175 points
Other Parts Discussed in Thread: AM1808

TI Team,

The USB pins USB0_ID (P16) and USB_VBUS (N16) are specified as analog signals;

  1.  What are the electrical specifications of these two pins?
  2. Where is the functional description of exactly how these pins are to be used/operated?
-David
  • 0
    TI__Guru**** 177676 points

    David

    1. For ID pin, min voltage is 0V and max voltage is 3.3V. For VBUS, min voltage is 0V and max voltage is 5.25V.

    2. Please refer to USB 2.0 spec and USB OTG spec. The ID pin is used in OTG application to determine whether the AM1808 is a host or a device. For AM1808 to be a  host, ID pin is tied to GND. For AM1808 to be a peripheral, it is left floating. The VBUS is used as a sensing pin. When the voltage on VBUS reaches greater than 4.01V, then AM1808 knows it needs to initiate the USB connect event. Please refer to Figure 7-29 of the USB 2.0 spec for more detail.

    Thanks
    David