Power Sources

The SAM L21 Xplained Pro kit can be powered by several power sources as listed in the table below.

Table 1. Power Sources for SAM L21 Xplained Pro
Power input Voltage requirements Current requirements Connector marking
External power 5V ±2% (±100mV) for USB host operation. 4.3V to 5.5V if USB host operation is not required. Recommended minimum is 1A to be able to provide enough current for connected USB devices and the board itself. Recommended maximum is 2A due to the input protection maximum current specification. PWR
Embedded debugger USB 4.4V to 5.25V (according to USB spec.) 500mA (according to USB spec.) DEBUG USB

The kit will automatically detect which power sources are available and choose which one to use according to the following priority:

  1. 1.External power.
  2. 2.Embedded Debugger USB.
Info: External power is required when 500mA from a USB connector is not enough to power the board with possible extension boards. A connected USB device in a USB host application might easily exceed this limit.