Hi Guys, I am working on a project involving mini usb connection. I know this is probably the wrong place to post such question, but be a good embedded engineer, I suppose we still need to know some basic stuff about circuit diagram.
So here is the Circuit diagram:
By gpakillsme at 2012-08-09[/img]
Few places I dont understand, hope anyone could answer it.
1. for VBUS why there are two caps there?
2. between GPIO and mini usb connector, both USB_VBUS,PA11,PA12 have a Resistor in between, what's the reason to put a R there?
3. Last question, sounds stupid. Based on description, the USB_PWR is used to power external usb device, why putting a bipolar transistor there?
Really appreciate your answer!