I need the ability to regulate two voltages (2.7V & 3.1V) for a single power supply. I was planning on using the LTC3025-1 and wanted to know if it was possible to connect two of these regulators outputs together but only enable one regulator to get 2.7V or enable the other regulator to get 3.1V. Is this possible or is there a better way ? Thanks.
Yes, you can parallel two LDOs with different output voltages. Putting two "Ideal Diodes" (https://www.analog.com/en/parametricsearch/11029), one on each output would avoid most issues. However, since you're using an LDO, you probably want the fewest parts between your clean LDO output and your load. Instead of your proposed solution where a signal can choose which LDO to turn on, you could add a circuit to a single LDO where a signal changes the resistance from ADJ to GND. This would allow one LDO to supply two output voltages, depending on the state of a digital signal.