Input driver for a differential folder employing a static reference ladder

An input driver for use with a differential folder in a flash A/D converter having a static ladder that provides an array of reference voltages and a method of operation thereof. The input driver includes a differential signal driver, coupled to an AC input signal, that generates first and second complementary drive signals for a differential folder stage. A tracking circuit, coupled to the differential signal driver, is utilized to maintain a voltage at the center of the static ladder to improve common mode rejection of the input driver without reducing bandwidth. In a related embodiment, the voltage at the center of the static ladder is an average DC voltage of the first and second drive signals.