3.4 Power Sources

The ATtiny817 Xplained Pro kit can be powered by several power sources, as listed in the following table.

Table 3-4. Power Sources for ATtiny817 Xplained Pro
Power SourceVoltage RequirementsCurrent RequirementsConnector Marking
External power5V ±2% (±100 mV) for USB host operation. 4.3V to 5.5V if a USB host operation is not required. The recommended value for the maximum current is 2A. PWR
Embedded debugger USB4.4V to 5.25V (according to USB specification)500 mA (according to USB specification)DEBUG USB

The kit automatically detects the available power sources and chooses which to use according to the following priority:

  1. External power.
  2. Embedded debugger USB.
Info: External power is required when 500 mA from a USB connector is not enough to power the board with possible extension boards.