The 74LS series of integrated circuits (ICs) was one of the most popular logic families of transistor-transistor logic (TTL) logic chips. 74LS series is a bipolar, low-power Schottky IC. 74LS155 monolithic transistor-transistor-logic (TTL) circuits feature dual 1-line-to-4-line demultiplexers with individual strobes and common binary-address inputs in a single 16-pin package.

74LS155 Features
- Contains Two Demultiplexers To Convert Serial Data to Parallel Output
- Input Clamping Diodes
- Low Power
- Operating Temperature up to 70°C
- Standard TTL Switching Voltages
74LS155 Specifications
Supply Voltage | 4.75 – 5.25Vdc |
Maximum Clock Frequency | 40Mhz |
Power Dissipation | 2mW/gate @100kHz |
Minimum Output Current | 8mA |
Propagation Delay | 10nS |
Fan Out (TTL Loads) | 20 |
74LS155 Pinout Diagram

74LS155 Pin Description
Pin No | Pin Name | Description |
1 | Ea | Enable Input Pin a |
2 | Ea | Enable Input Pin a |
3 | A1 | Data Input Pin of A1 |
4 | O3a | Output Bit 3 of a |
5 | O2a | Output Bit 2 of a |
6 | O1a | Output Bit 1 of a |
7 | O0a | Output Bit 0 of a |
8 | GND | Ground Pin |
9 | O0b | Output Bit 0 of b |
10 | O1b | Output Bit 1 of b |
11 | O2b | Output Bit 2 of b |
12 | O3b | Output Bit 3 of b |
13 | A0 | Data Input Pin of A0 |
14 | Eb | Enable Pin b |
15 | Eb | Enable Pin b |
16 | VCC | Positive Supply |
74LS155 Circuit
Applications
- Connect a single source to multiple destinations
74LS155 Alternative Equivalent
74LS156
Download 74LS155 Dual 2/4 Demultiplexer Datasheet from the link given below.