Nxp 4000 series logic devices nxp hef4044bt the hef4044b is a quad rs latch with 3 state outputs with a common output enable input oe each latch has an active low set input 1s to 4s an active low reset input 1r to 4r and an active high 3 state output 1q to 4qwhen oe is high the latch output nq is determined by the nr and ns inputs when oe is low the latch outputs are in the high impedance off state oe does not affect the state of the latch the high impedance off state feat