These data selectors multiplexers contain full on-chip binary decoding to select one-of-eight data sources and feature a strobe-controlled TRI-STATE output The strobe must be at a low logic level to enable these devices The TRI-STATE outputs permit direct connection to a common bus When the strobe input is high both outputs are in a high-impedance state in which both the upper and lower transistors of each totem-pole output are off and the output neither drives nor loads the bus significantly When the strobe is low the outputs are activated and operate as standard TTL totempole outputs To minimize the possibility that two outputs will attempt to take a common bus to opposite logic levels the output control circuitry is designed so that the average output disable time is shorter than the average output enable time