The comparator creates a window of operation between ¼ Vdd and ⅔ Vdd. If the voltage across Cs drops below ¼ Vdd, the output of comparator 2 will go HIGH. If the voltage across Cs rises above ⅔ Vdd, the comparator 1 output will go LOW because of the inverted output. Both comparator 1 and comparator 2 outputs enter into the SR Flip-Flop’s Set and Reset inputs respectively.