I'm working on a design using the usb0 port from the ADSP-BF707 and the isolator ADUM4160. The USB will ever be in peripheral mode. I found some guidelines how to connect the USB0_ID and USB0_VBUS pins in peripheral mode but no information about the USB0_VBUS pin. In the datasheet of the ADUM4160 in Figure 4 is a typical application as peripheral shown where VDD2 and VBUS2 is connected to 3.3V. In my design I connect it the same way.
My question is:
How do I have to connect the USB0_VBUS pin at the BF707 in peripheral mode? Can I left the pin open or connect it to ground or do I have to connect the USB0_VBUS pin also to 3.3V for correct operation. The VDD_USB voltage is 3.3V.
Thanks for helping.
Please refer the ADSP-BF707 Ez-Kit schematics for your reference,
In the ADSP-BF707 Ez-Kit schematics the USB0_VBUS pin is connected to 5V to handle the otg functionality. I don’t have a 5V power supply on my board and the datasheet of the ADUM4160 in figure 4 the connection of VBUS2 and VDD2 is 3.3V.
I ask again, how I should connect the USB0_VBUS pin on the BF70x family. Do I really must connect the pin to 5V as in the Ez-Kit schematic shown when I have the ADUM4160?
USB0_VBUS is an input voltage to the processor and, according to the USB 2.0 specification, it should be sourced externally from the USB connector (when operating in peripheral mode) – 5V are required, as per the spec.
The EZ-KIT schematics Jithul pointed you to in his previous response, show a good example of USB protection circuitry, which is required to prevent damaging the device, when USB power is on (from the external source) and the Blackfin processor is not powered.