Qin the ad8611 data sheet you are refering to "overdrive".
What is overdrive ?
AOverdrive in a comparator is the difference in voltage between the + and -
inputs. If the threshhold is set at 2.5V, connected to the -ve input, and the
+ve input is a square wave which switches between 2.3V and 2.6V then the
overdrive is 0.1V for a rising edge input and 0.2V for a falling edge input.
Overdrive has an effect on the propagation delay of the comparator, as shown in
figure 2 of the datasheet.