CD74AC74E

Overview

The CD74AC74E is a dual D-type flip-flop manufactured by Harris Corporation, belonging to the AC logic series. It features two independent circuits within a single package, utilizing CMOS technology for low power consumption and high noise immunity. The device operates with a supply voltage range of 2V to 6V and supports through-hole mounting in a standard 14-pin PDIP package. Key electrical characteristics include a maximum propagation delay of 135 ns at nominal supply conditions and a load capacitance rating of 50 pF. The component is designed for robust performance across an extended industrial temperature range from -55°C to +125°C, ensuring reliability in demanding environments.

Feature Summary

• Dual independent D-type flip-flop configuration within a single integrated circuit package
• CMOS construction providing high noise immunity and low static power consumption
• Wide operating supply voltage range supporting both 3.3V and 5V logic systems
• Industrial-grade temperature rating suitable for harsh environmental conditions

Applications

• Parallel-to-serial data conversion circuits
• Shift register implementations for digital signal processing
• General-purpose storage elements in microprocessor-based systems
• Timing control and synchronization logic in industrial automation

Procurement Notes

Verify manufacturer origin as Harris Corporation or authorized successor entities like Intersil or Texas Instruments, noting historical acquisition chains. Confirm RoHS compliance status, as original Harris versions may be non-compliant compared to modern equivalents. Ensure the PDIP-14 package matches mechanical constraints. Validate that the AC series designation aligns with required speed and voltage specifications for the target application design.

Selection Notes

Select this component when dual D-latch functionality is required with AC-series speed characteristics. Compare against HC or HCT families if lower cost or specific TTL compatibility is needed, noting voltage differences. Consider the 135 ns propagation delay for timing-critical paths. Verify that the 14-pin DIP form factor fits the PCB layout requirements. Assess thermal management needs given the wide operating temperature range capability.

Part Context

The CD74AC74E belongs to the widely adopted 74AC logic family, known for high-speed operation and compatibility with standard CMOS interfaces. Originally developed by Harris Semiconductor, this part number represents a legacy component now often managed by successors such as Intersil or Texas Instruments following corporate acquisitions. It serves as a fundamental building block in digital electronics, offering reliable state retention capabilities for sequential logic designs.

Replacement Considerations

Public confirmed substitute part numbers include CD74HC74E (HC series) and CD74ACT74E (ACT series). These alternatives offer similar pinouts and logical functions but differ in speed, power consumption, and input threshold voltages. Verify voltage compatibility and switching speeds before substitution to ensure circuit integrity.