74AC280SCX

Overview

The Fairchild Semiconductor 74AC280SCX is an octal phase accumulator integrated circuit belonging to the AC logic family. It features eight D-type flip-flops with a common clock input and provides nine outputs: one Q output and eight inverted Q-bar outputs per stage, effectively creating a modulo-512 counter when cascaded. The device operates within a supply voltage range of 2.0V to 6.0V. Key electrical characteristics include a propagation delay of typically 10ns at 5V and a high noise immunity level. It is housed in a 20-pin Small Outline (SOIC) package.

Feature Summary

• Provides octal phase accumulation functionality through eight synchronized D-type flip-flops
• Generates complementary Q and Q-bar outputs for each bit position
• Capable of forming higher-order counters via serial cascading of multiple units
• Operates across a wide DC supply voltage range compatible with standard logic levels

Applications

• Digital signal processing systems requiring phase accumulation
• Frequency synthesis circuits utilizing direct digital synthesis techniques
• High-speed data acquisition systems needing precise timing control
• Modulo-N counter implementations in digital instrumentation

Procurement Notes

Verify the specific suffix 'SCX' against the manufacturer's current datasheet to confirm package type and tape-and-reel specifications. Ensure the component meets RoHS compliance requirements if applicable to your assembly process. Cross-reference the date code and lot number with authorized distributors to guarantee authenticity and traceability. Confirm that the operating temperature range aligns with your system's environmental constraints before finalizing procurement.

Selection Notes

Select this component when designing circuits requiring octal phase accumulation or high-speed counting capabilities within the AC logic family. Consider the 2.0V to 6.0V supply range compatibility with your system's power rails. Evaluate the propagation delay specifications against your maximum clock frequency requirements. Ensure the SOIC package footprint matches your PCB layout constraints and manufacturing capabilities.

Part Context

This part belongs to Fairchild's 74AC series of advanced CMOS logic devices, known for high speed and low power consumption. The 74AC280 specifically addresses phase accumulation needs, differing from standard counters by providing both true and complemented outputs simultaneously. It serves as a building block for complex digital systems requiring precise phase management or frequency division functions.

Replacement Considerations

Direct substitutes may include other manufacturers' 74AC280 variants with identical pinouts and electrical characteristics. Verify functional equivalence regarding propagation delays and supply voltage ranges. Check for any differences in output drive strength or noise immunity specifications. Ensure mechanical dimensions match for drop-in replacement without PCB redesign.