A system comprising: a LDO regulator configured to receive a supply voltage and provide an output voltage based on a function of the supply voltage, the LDO regulator switchable between at least a first and second mode, wherein the first and second modes each define the output voltage provided to the output terminal based on different functions of the supply voltage; and a digital logic controller configured to select the mode of the LDO regulator by control signalling to the LDO regulator, the digital logic controller configured to receive power for the provision of the control signalling from the LDO regulator; wherein the LDO regulator comprises LDO start-up circuitry configured to cause the LDO regulator, during start-up, to default to a predetermined one of the first and second mode and the LDO start-up circuitry further configured to prevent the digital logic controller from controlling the mode of the LDO regulator.