I'm building a 12bit multichannel thermometer/controller using thermistors and a MAX186 amongst other things.
I need opinions on the analog side. The MAX186
datasheet will not tell me the input impedance of the analog inputs.
I want to use a voltage divider with one precision resistor and a thermistor between Vref and ground.
It is advantageous to use higher resistance (100K-1M) thermistors because there is less selfheating, but that leads to the question.
Would I need to buffer the inputs to prevent the ADC itself affecting the reading?
Thinking of a LM339 as a voltage follower, is this a stable solution? i.e. will it oscillate?
I'd like to avoid avoid extra circuitry.
Cheers
Incoherent