Switching between DCDC and LDO power supply

[BIBINLUKOSE]

Hi 

We are using Nordic NRF52840 in our design. Normally we are using DCDC mode with VDD and VDDH together [Normal mode] connected to 2.2V. In a special case we wanted to switch DCDC to LDO mode to mitigate a failure situation. Later we want to switch it back to DCDC after that situation. So can you explain what would happen to this chip, when we make this switch? Would it reset the chip? Would it reset the connection? If it reset, would it be an entire chip reset or a portion [like RAM]  will get reset?

thanks 

[Stian Røed Hafskjold]

Hi, you can enable and disable the DCDC regulator seamlessly. There will be no resets. The DCDC regulator is already being switched on and off automatically by the internal power management.

If DCDC is enabled the regulator switches between ULP mode and DCDC.

If DCDC is disabled the regulator switches between ULP mode and LDO.

ULP (ultra low power) is a type of LDO regulator which is only used for low current draws because of the very low quiescent current.

If you use the softdevice you can use the softdevice API nrf_power_dcdc_mode_set(), otherwise you can use the register directly.