SLAU533D September 2013 – April 2017
In certain situations, it is advantageous to have an external 5-V source and USB connected simultaneously (see Figure 20). The USB connection may be needed for direct USB communication, back-channel UART, or to allow for programming through emulation. In this scenario, the 5V jumper in the isolation block must be disconnected to allow for the two separate 5-V sources. If using external power source for both 3.3 V and 5 V, consider recommendations for each.