Normal voltage mode uses the main regulator (VREGMAIN) and the radio regulator (VREGRADIO).
The VREGMAIN and VREGRADIO regulators operate in LDO mode by default. DC/DC mode is enabled independently for each regulator using VREGMAIN.DCDCEN (Retained) and VREGRADIO.DCDCEN (Retained) respectively.
When configured as shown in the following figure, nRF5340 enters normal voltage mode. Here both regulators are in DC/DC mode. An external LC filter is required for each regulator in DC/DC mode. If a regulator is only to be used in LDO mode, the inductor for this regulator is not needed. In this mode, the VDDH pin must be connected to VDD, even if the high voltage regulator (VREGH) is not in use.
Operating a regulator in DC/DC mode reduces the overall power consumption due to higher efficiency than in LDO mode. Regulator efficiency in DC/DC mode varies depending on the supply voltage and the current drawn from the regulators.