Nxp 4000 series logic devices nxp hef4585bp 652 the hef4585b is a 4 bit magnitude comparator that compares two 4 bit words a and b and determines whether a is greater than b a is equal to b or a is less than b each word has four parallel inputs a0 to a3 and b0 to b3 with a3 and b3 being the most significant inputs three outputs are provided a greater than b qagtb a less than b qaltb and a equal to b qab three expander inputs iagtb ialtb and iab allow cascading o