R4 is thermistor with
R25 value of
Beta is 3150.
V should be at most
1V because I want to use internal
1V1 reference voltage.
V supply is 5V. I don't really want to use OpAmp to keep it simple. The problem is also to draw as less current from power supply as possible. Accuracy can be 2-3C, range is 20-80C.
I tried to use some Wheatstone bridge calculators, but I don't get the bridge balanced and to draw acceptable current.