Abstract: Comparator systems are provided that include first and second differential pairs of transistors with inherent offsets that are a function of their tail currents. Some system embodiments configure the pairs to have substantially-equal, nonzero inherent offset voltages and other embodiments configure them to have substantially-zero inherent offset voltages. The systems further include a feedback network arranged to provide a second tail current to the second differential pair that substantially nulls the second output signal of this differential pair when it is driven by a reference signal. The feedback network generates an identical first tail current for the first differential pair which will now accurately compare an input signal to the reference signal.

Abstract: Comparator systems are provided that substantially enhance comparator dynamic range. The enhancement is primarily realized by arranging the systems to apply comparator input signals at feedback taps positioned between the upper and lower ends of comparator strings of impedance elements.