| Technology Family | ALS |
| Function | Digital Multiplexer |
| Configuration | 8:1 |
| Number of channels (#) | 1 |
| Operating temperature range (C) | -55 to 125 |
| Rating | Military |
- 3-State Version of the ′ALS151
- 3-State Outputs Interface Directly With System Bus
- Perform Parallel-to-Serial Conversion
- Complementary Outputs Provide True and Inverted Data
- Package Options Include Plastic Small-Outline (D) Packages, Ceramic Chip Carriers (FK), and Standard Plastic (N) and Ceramic (J) 300-mil DIPs
These data selectors/multiplexers contain full binary decoding to select one-of-eight data sources and feature controlled complementary 3-state outputs.
The 3-state outputs can interface with and drive data lines of bus-organized systems. With all but one of the common outputs disabled (at the high-impedance state), the low impedance of the signal-enabled output drives the bus line to a high or low logic level. Both outputs are controlled by the output-enable (OE\) input. The outputs are disabled when 
is high.
The SN54ALS251 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ALS251 is characterized for operation from 0°C to 70°C.
D0, D1,...D7 = the level of the respective D input