I have a voltage divider circuit that cuts an input voltage in half. The half voltage is fed into an ADC. I need this reading to be stable over temperature. The resistors are 100K, but I don't think this matters.
Do I need to use resistors that have a low temperature coefficient to have a stable reading?
Or, because the resistors are the same value and have approximately the same temperature coefficient, can I use standard resistors? The resistors will track each other over temperature and the midpoint will always be half the input voltage.
Best Answer
Like Olin I was thinking of a resistor array. (Array being a big word for two resistors in a single package.) Firstly, being manufactured on the same process will give you a good matched value, and secondly being in the same package will make their temperatures also matching. At Vishay I found these "High Precision Thin Film Chip Resistor Arrays":
edit
Linear Technology has the LT5400 resistor array with the following specs:
Prices start at USD 3.49 quantity 1000, so that's pretty steep. For a couple of resistors, that is.