To set the reference voltage level for the General-Purpose Input/Output (GPIO)s and the TWI, use a jumper to connect either VOUT1 or VOUT2 to VDDIO on P18.
When using the default jumper configuration on the Evaluation Kit (EK), VDDIO is supplied locally by VOUT2 on P18.
Figure 1. VDDIO schematic
Note: The minimum VDDIO voltage is 1.7 V. Any lower
voltage can result in lost TWI communication between host and nPM1300
Power Management Integrated Circuit (PMIC).
Note: If VDDIO is supplied externally, leave the
jumper on P18 unconnected.
See VDDIO for more information on external supply.