Rochester Electronics 54AC251/VFA-R

'AC/'ACT251 is a high-speed 8-input digital multiplexer. It provides the ability to select one bit of data from up to eight data sources in a single package. It can be used as a universal function generator to implement any logic function of four variables. The device provides both true and complemented outputs.

The device is a logic implementation of a single-pole 8-position switch, with the switch position controlled by the states of three select inputs S0, S1, S2. Both true and complemented outputs are provided. The output enable input (OE̅) is active LOW. When activated, the logic function at the output is: Z = OE̅ × (I0 × S̅0 × S̅1 × S̅2 + I1 × S0 × S̅1 × S̅2 + I2 × S̅0 × S1 × S̅2 + I3 × S0 × S1 × S̅2 + I4 × S̅0 × S̅1 × S2 + I5 × S0 × S̅1 × S2 + I6 × S̅0 × S1 × S2 + I7 × S0 × S1 × S2)

When the output enable is HIGH, both outputs are in the high-impedance (high-Z) state. This feature allows multiplexer expansion by connecting the outputs of up to 128 devices together. When the outputs of three-state devices are connected together, all but one device must be in the high-impedance state to avoid excessive current that would exceed maximum ratings. The output enable signals must be designed so that the active LOW portions of the enable voltages do not overlap.

These devices have limited built-in ESD protection. During storage or handling, pins should be shorted together or the devices placed in conductive foam to prevent electrostatic damage to the MOS gates.

• 50% reduction in quiescent current (Icc)
• Multifunction capability
• On-chip select logic decoding
• Inverting and non-inverting three-state outputs
• Output source/sink current 24 mA
• 'ACT251 with TTL-compatible inputs
• Standard Military Drawing (SMD)
• 'AC251 part number: 5962-87692
• 'ACT251 part number: 5962-89599