74285 4-bit by 4-bit Parallel Binary Multiplier IC DIP-16
These high-speed TTL circuits perform positive-logic multiplication of two 4-bit binary words to produce an 8-bit product. Designed for high-performance, parallel multiplication uses, the device generates the eight-bit binary product with a typical delay of about 40 ns, making it suitable as a fast arithmetic building block in digital systems.
The basic 4×4 multiplier is intended to be used as a fundamental building block for larger multipliers: multiple 4×4 devices can be combined to form 8×8, 16×16 (via partial-product summation such as Wallace trees), and other N×M multipliers. The datasheet illustrates how chaining these elements and using carry-save adders produces wider products with minimal added delay.
Characterized for standard TTL environments, the part is fully compatible with TTL logic families and includes diode-clamped inputs to simplify system design. Pinouts and timing diagrams are provided so designers can integrate the device into arithmetic units, multiply-accumulate structures, or custom ALU arrangements.
Features:
- Fast multiplication of two 4-bit binary numbers 8-bit product in ~40 ns.
- Expandable for N-bit × n-bit applications (examples: 16-bit product in ~70 ns, 32-bit in ~103 ns).
- Fully compatible with most TTL circuits.
- Diode-clamped inputs to simplify system design.
Specifications:
| Specification | Value (SN74285N) |
|---|---|
| Function: | 4-bit × 4-bit parallel binary multiplier |
| Logic family: | High-speed TTL |
| Supply voltage (VCC): | 4.75 V to 5.25 V (nominal 5 V) |
| Absolute maximum VCC: | 7 V |
| Input high voltage (VIH): | Minimum 2.0 V |
| Input low voltage (VIL): | Maximum 0.8 V |
| Output high current (IOH): | 40 µA |
| Output low current (IOL): | Up to 16 mA |
| Output low voltage (VOL): | 0.45 V (max at 16 mA) |
| Typical propagation delay: | ~40 ns (input to product output) |
| Enable to output delay: | ~20–30 ns |
| Supply current (ICC): | 92 mA to 130 mA |
| Operating temperature range: | 0 °C to +70 °C |
| Package type: | DIP-16 (N-package) |
| Number of output bits: | 8-bit binary product |
Pinout:
Applications:
- High-Speed Digital Signal Processing.
- Arithmetic Logic Unit (ALU) Expansion.
- Microprocessor Based Systems (Hardware Multiplier).
- Instrumentation and Measurement Circuits.
- Digital Filter Design.
- Process Control Logic.
- Video and Graphics Data Manipulation.
- Minicomputer and Peripheral Interface.
Package Contents:
- 1x 742854-bit by 4-bit Parallel Binary Multiplier IC DIP-16
