Backup Battery

The SAM L21 Xplained Pro has a backup battery for use with the SAM L21 backup module. The battery can be connected to the device by placing a jumper over pin 1-2 on the 3-pin VBAT SELECT header.

By default the jumper is placed over pin 2-3 to select the board power supply. This configuration is selected to avoid draining the battery and can be used during development.

Table 1. VBAT SELECT Header
VBAT SELECT pin Function
1 Power from battery
2 PB03/VBAT pin on SAM L21
3 Power from board supply