74F382PC

Overview

The onsemi 74F382PC is a 4-bit Arithmetic Logic Unit (ALU) housed in a 20-lead Plastic Dual-In-Line Package (PDIP). It performs arithmetic and logic operations on two 4-bit words, A and B. The device operates within a supply voltage range of +4.5V to +5.5V and supports an ambient temperature range of 0°C to +70°C. Key electrical parameters include a maximum propagation delay of 17.5ns from Select inputs to Function outputs at 0°C. The circuit provides a Carry output for ripple expansion and an Overflow output for two's complement arithmetic.

Feature Summary

• Performs six distinct arithmetic and logic functions including addition, subtraction, and bitwise operations via three Select input codes.
• Includes dedicated Carry output for ripple expansion and Overflow output for detecting two's complement arithmetic errors.
• Features selectable LOW (clear) and HIGH (preset) functions to force specific output states independent of operand data.

Applications

• Ripple expansion configurations for multi-bit arithmetic processing
• Two's complement arithmetic systems requiring overflow detection
• High-speed expansion using Carry Lookahead Generators

Procurement Notes

Verify the package type matches the required footprint, as the 74F382 series includes SOIC and SOP variants alongside the PDIP option. Confirm that the operating temperature range meets system requirements, as this specific part number is rated for commercial temperatures only. Ensure compatibility with existing logic families regarding input loading and drive capabilities before finalizing procurement.

Selection Notes

Select this component when a 4-bit ALU with explicit overflow and carry outputs is required for parallel data processing. Consider the propagation delays relative to system clock speeds, particularly for paths involving Select inputs or Carry chains. Evaluate the unit loading characteristics to ensure downstream drivers can handle the specified current loads without signal degradation.

Part Context

The 74F382 belongs to the 74F logic family, characterized by high-speed performance compared to standard TTL. Originally manufactured by Fairchild Semiconductor, the product line was acquired by onsemi. This specific model serves as a fundamental building block for digital arithmetic circuits, offering a balance of speed and functional versatility for general-purpose computing tasks.

Replacement Considerations

Direct substitutes may include other 74F-series 4-bit ALUs from different manufacturers. Verify pinout compatibility and electrical specifications such as propagation delay and power consumption. Note that while functionally similar, variations in packaging or temperature ratings may require design adjustments.

FAQ

How is the Overflow output determined?

The Overflow output (OVR) is generated by the Exclusive-OR of the carry into the most significant bit (Cn+3) and the carry out of the most significant bit (Cn+4). A HIGH signal indicates an overflow in two's complement operation.

What is required for Subtract operations?

For Subtract operating modes, it is necessary to force a carry into the Cn input of the least significant package. For active HIGH operands, this requires a HIGH signal; for active LOW operands, a LOW signal is required.