Similar to the 74LS151 / 74151 (8-input multiplexer) version, this package contains two separate (4-input) circuits. The logic diagram to the right, illustrates the point. Each independent circuit within can be 2-bit binary selected to choose one of four source pins. The digital value at the specified source will be reflected on the device's output. Each of the two circuits is capable of the same function. Applications include, computer bus architecture, run-time selectable digital streams, electronic mathematical processing, etc.

The LSTTL/MSI SN54/74LS153 is a very high speed Dual 4-Input
Multiplexer with common select inputs and individual enable inputs for each
section. It can select two bits of data from four sources. The two buffered
outputs present data in the true (non-inverted) form. In addition to multiplexer
operation, the LS153 can generate any two functions of three variables. The
LS153 is fabricated with the Schottky barrier diode process for high speed and
is completely compatible with all Motorola TTL families.
• Multifunction Capability
• Non-Inverting Outputs
• Separate Enable for Each Multiplexer
• Input Clamp Diodes Limit High Speed Termination Effects