MC74AC573NG ON Semiconductor

MC74AC573, MC74ACT573 Octal Buffer/Line Driver with 3State Outputs The MC74AC573/74ACT573 is a highspeed octal latch with buffered common Latch Enable (LE) and buffered common Output Enable (OE) inputs. MC74AC573, MC74ACT573 Functional Description TRUTH TABLE The MC74AC573/74ACT574 contains eight Dtype Inputs Outputs latches with 3state output buffers. When the Latch Enable OE LE D O (LE) input is HIGH, data on the D inputs enters the latches. n n n In this condition the latches are transparent, i.e., a latch L H H H output will change state each time its D input changes. When L H L L LE is LOW the latches store the information that was present L L X O 0 on the D inputs a setup time preceding the HIGHtoLOW transition of LE. The 3state buffers are controlled by the H X X Z Output Enable (OE) input. When OE is LOW, the buffers are H = HIGH Voltage Level enabled. When OE is HIGH the buffers are in the high L = LOW Voltage Level Z = High Impedance impedance mode but this does not interfere with entering X = Immaterial new data into the latches. O = Previous O before LOWtoHIGH Transition of Clock 0 0 D D D D D D D D 0 1 2 3 4 5 6 7 D D D D D D D D Q Q Q Q Q Q Q Q LE LE LE LE LE LE LE LE LE OE O O O O O O O O 0 1 2 3 4 5 6 7 NOTE: That this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays. Figure 3. Logic Diagram