SAM V71 Xplained Ultra has four power sources as described in Power Sources. Figure 1 shows a block diagram of the power supply circuitry, the related I/O pins are described in Table 1.
The kit can be powered from the EDBG USB, Target USB, external 5.0V, and/or a 5-14V DC jack input. The kit will automatically select a source to draw power from.
An on board supercap (100mF) is charged to 3.6V from the kits 5V net. When all external power is removed from the board or the 3.3V regulator is disabled by the application running on the ATSAMV71Q21 the power switch will supply the ATSAMV71Q21 from the supercap. It is intended that the supercap can supply the ATSAMV71Q21 in its low power backup mode.
| SAM V71 pin | Function | Description |
|---|---|---|
| PC17 | GPIO | Power Enable, drive low to disable the on-board voltage regulator |
| PA01 | WKUP1 | Regulator Power Detect, pulled high when the regulator output is good |
| PC16 | GPIO | Drive low to enable the kit to supply the target USB |