Hi,
Thanks for the response! ;o) I can't find any reference to common mode voltages in any of the datasheets. Just to clarify, if you take the higher input voltage and subtract the difference between the higher and lower input voltages will that give you the common mode voltage? If there is an upper limit to the CMV, does this then mean that if both of the input signals are above this then the comparator will not behave as designed? If this is the case, then this is what has confused me as it is clearly specified that either of the input signal voltages can swing from -ve to +ve supply, i.e. 0V-5V, and with lack of mention of a common mode voltage, this implies that the comparator will switch with inputs signals right up to the supply voltage. Is an upper CMV limit that is well below the supply voltage ( 3.9V in my case with the 311? ) normal with all comparators, and if so, why is there no mention of this in the datasheets?
Thanks again!