The goal is to supervise a large kind of sensor devices, these devices uses dual resistors in order to get 4-states information.
I will use a stabilized 1,2VDC as source, crossing a voltage divider resistor where R1 is the resistance value inside the sensor. The sensor can have any kind of resistor values, even no resistors (dry contact).
I could define the resistors value to use in sensors and it's done, but I would like to keep the freedom of using any kind.
Don't care about Adjusting the voltage tolerance and threshold, that will be made at higer level by the "master IC ADC" (14bits resolution), and can be changed for each input by software...
I dont want to detect a value with the component that I'm searching for, I just want to give an information of any change of minimum 10mV from the sensor circuit, in order to wake my ADC and sample the value...
-> the voltage change will be always fast, because the information come from a switch
I think my needs is so simple, that you look too far
Now I rephrase my question; do you now an IC able to sense (for example at 4Hz) an analog voltage (in a range of 0 to 1,2V), record the previous value and compare with the next in order to pulse (200mS, automatic reset) an output in case of voltage variation (10 mV minimum)?
Thank you
Eki