USB_VBUS

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xlordofpainx
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Joined: Thu Mar 08, 2018 2:44 pm

USB_VBUS

Post by xlordofpainx »

Long time no see,

Here is my question: I want to have only usb Input to the xmos board, no output. But I have connected the vbus via a diode to the power input of my schematic(custom board) so that it does not conflict with the other 5V input. Do I still need to connect the USB_CBUS to the USB_VBUS pin? I did read the document:"
If you use the USB PHY to design a self-powered USB-device, then the device must
be able detect the presence of VBus on the USB connector (so the device can
disconnect its pull-up resistors from D+/D- to ensure the device does not have
any voltage on the D+/D- pins when VBus is not present, “USB Back Voltage Test”).
This requires USB_VBUS to be connected to the VBUS pin of the USB connector as is
shown in Figure 15."

But I am not sure whether I should still make this connection. Again- I am going to be having usb Audio going to the board, but nothing going out and it will use the 5V to power itself directly going to the buck converters