Many simple thermometers rely on a PN junction sensor because of its -1.8mv/c tempco.
All that I have seen use 1/2 of a transistor for the PN junction.
Diodes have the same tempco, so why aren't they popular for use as the sensor?
Are transistors cheaper than diodes, or is this some kind conspiracy?
They are not easy to bolt to things. I built an amp with 3 diodes in series mounted on the heatsink. It took two holes. Two diodes are a press fit and the other lays on top of the heat sink. Not good for production.