A 3.6V Zener will probably leak too much at 3.3V compared to a 100K thermistor so low temp readings will be inaccurate.
If the thermistor is shorted to 12V D502 will conduct and put 12V on the 3.3V rail destroying the MCU.
Can't see the point of the PTC. 290mA into a CMOS input for 0.2s will blow the crap out it.
If the thermistor is shorted to 12V D502 will conduct and put 12V on the 3.3V rail destroying the MCU.
Can't see the point of the PTC. 290mA into a CMOS input for 0.2s will blow the crap out it.