DM74ALS874B

DM74ALS874B Dual 4-Bit D-Type Edge-Triggered Flip-Flop with 3-STATE Outputs April 1984 Revised February 2000 DM74ALS874B Dual 4-Bit D-Type Edge-Triggered Flip-Flop with 3-STATE Outputs General Description This dual 4-bit register features totem-pole 3-STATE outputs designed specifically for driving highly-capacitive or relatively low-impedance loads. The high-impedance state and increased high-logic-level drive provide this register with the capability of being connected directly to and driving the bus lines in a bus-organized system without need for interface or pull-up components. It is particularly attractive for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers. The eight flip-flops of the DM74ALS874B are edge-triggered D-type flip-flops. On the positive transition of the clock, the Q outputs will be set to the logic states that were set up at the D inputs. A buffered output control input can be used to place the eight outputs in either a normal logic state (HIGH or LOW logic levels) or a high-impedance state. In the high-impedance state the outputs neither load nor drive the bus lines significantly. The output control does not affect the internal operation of the flip-flops. That is, the old data can be retained or new data can be entered even while the outputs are OFF. Features s Switching specifications at 50 pF s Switching specifications guaranteed over full temperature and VCC range s Advanced oxide-isolated, ion-implanted ...