74181 Arithmetic Logic Unit/Function Generator 5V IC DIP-24
The 74181 Arithmetic Logic Unit (ALU) is a classic TTL integrated circuit that performs high-speed 4-bit arithmetic and logic operations. It is capable of executing 16 arithmetic functions and 16 logic functions, making it a fundamental building block in early microprocessors, minicomputers, digital controllers, and educational computer architecture projects. The operation is selected through four function-select inputs and a mode control input, allowing flexible implementation of mathematical and logical computations.
Designed for expansion into wider data paths, the 74181 supports carry propagation and carry look-ahead operation when used with external carry look-ahead circuitry. It provides outputs for carry generate and propagate signals, enabling efficient cascading of multiple ALUs for 8-bit, 16-bit, or larger arithmetic systems. The IC remains popular for digital logic education, retro-computing projects, and custom CPU designs due to its versatility and historical significance.
Features:
- High-speed 4-bit Arithmetic Logic Unit.
- Performs both arithmetic and logic functions.
- Supports 16 arithmetic operations.
- Supports 16 logic operations.
- Function selection via four control inputs.
- Separate arithmetic and logic operating modes.
- Carry generate and carry propagate outputs.
- Carry look-ahead compatible.
- Easily cascaded for wider data processing.
- TTL logic compatible.
- Through-hole DIP package.
- Suitable for educational and industrial digital circuits.
- Reliable and proven architecture.
Specifications:
| TYPE | DESCRIPTION |
| Category | Integrated Circuits (ICs)
Logic |
| Series | 74LS |
| Logic Type | Arithmetic Logic Unit |
| Supply Voltage | 4.75V ~ 5.25V |
| Operating Temperature | 0°C ~ 70°C |
| Mounting Type | Through Hole |
| Package / Case | 24-DIP (0.600″, 15.24mm) |
| Base Product Number | 74LS181 |
Pin Configuration:
| Pin No | Pin Name | Description |
|---|---|---|
| 1 | B0‘ | Active low Operand Input B0‘ |
| 2 | A0‘ | Active low Operand Input |
| 3 | S3 | Function Select Input S3 |
| 4 | S2 | Function Select Input S2 |
| 5 | S1 | Function Select Input S1 |
| 6 | S0 | Function Select Input S0 |
| 7 | Cn | Carry Input |
| 8 | M | Mode Control Input |
| 9 | F0‘ | Function Output F0‘ |
| 10 | F1‘ | Function Output F1‘ |
| 11 | F2‘ | Function Output F2‘ |
| 12 | GND | Ground Pin |
| 13 | F3‘ | Function Output F3‘ |
| 14 | A=B | Comparator Output |
| 15 | P’ | Active low carry propagate |
| 16 | Cn+4 | Carry Output |
| 17 | G’ | Active low carry generator |
| 18 | B3‘ | Active low Operand Input B3‘ |
| 19 | A3‘ | Active low Operand Input A3‘ |
| 20 | B2‘ | Active low Operand Input B2‘ |
| 21 | A2‘ | Active low Operand Input A2‘ |
| 22 | B1‘ | Active low Operand Input B1‘ |
| 23 | A1‘ | Active low Operand Input A1‘ |
| 24 | VCC | Chip Supply Voltage |
Applications:
- Digital arithmetic circuits.
- Computer architecture projects.
- Educational CPU designs.
- Binary calculators.
- Logic processing systems.
- Digital control units.
- ALU expansion circuits.
- Industrial digital controllers.
- Retro computer restoration.
- Embedded digital logic systems.
Package Includes:
- 1x 74181 Arithmetic Logic Unit/Function Generator 5V IC DIP-24 (Wide).
Documents:
- 74181.