the simplest thermostat with programmable thresholds?

[danadak]

The application is for 12V. I haven't read the data sheet, but generally programmable devices are limited to 5V, so a regulator  (assuming it doesn't have an on chip regulator) and potential dividers are still required to scale the voltage down to something the device can handle.

Yes, supply range is 1.7 to 5.5, so a series zener would probably suffice, and A/D input would require R divider,
for battery monitoring. Thats also reason pass transistor base cannot be switched directly. Might be able to use
simple diode clamp and series R along with Open Drain config on PSOC. But for sure, as shown on schematic,
low current NPN takes care of that problem.


Regards, Dana.