App note from Linear Technology using their LTC2970 to monitor external temperature aside from doing power management. Link here (PDF)
Many applications with a single power regulator can benefit from the monitoring and control features of a power supply manager, but most power supply manager ICs have more than one channel. In an application that only has one power supply, there will be an unused set of DAC and ADC pins. Instead of letting the unused channel go to waste, we can use these pins, and a bit of microcontroller code, to sense remote temperature.
from Dangerous Prototypes https://ift.tt/2AlNBi2