The 74LS155 is a dual 1-of-4 decoder/demultiplexer IC with the following specifications:

• Supply Voltage (Vcc): 4.75V to 5.25V
• Logic Function: Two independent 2-to-4 line decoders with active low outputs.
• Input Low/High Voltage: 0.8V (max) / 2.0V (min)
• Output Current: High: -0.4mA, Low: 8mA
• Propagation Delay: Approximately 18ns (typical)
• Operating Temperature: 0°C to +70°C
• Package: Typically available in 16-pin DIP or SOIC.

It is commonly used in address decoding and memory selection applications. Refer to the datasheet for more details.