3.1.1.2 USB Supply Input

The USB-powered operation comes from the USB device port connected to a PC or a 5 VDC supply. The USB supply is enough to power the board in most applications. It is important to note that when the USB supply is used, the USB port has limited power. If a USB host port is required for the application, it is recommended to use the external DC supply or a more capable micro USB external power supply.

The following figure shows the USB input power supply topology.

Figure 3-3. USB Input Power Schematic

Note: USB-powered operation eliminates the need for additional wires and batteries. It is the preferred mode of operation for any project that requires only a 5V source at up to 500 mA.