74AC574SJ

Overview

The Fairchild Semiconductor 74AC574SJ is an octal D-type flip-flop featuring three-state outputs, housed in a 20-pin SOIC package. It operates within a voltage range of 2V to 6V and supports a maximum clock frequency of 28 MHz. The device provides high-speed performance with propagation delays as low as 13 ns at 5V. It includes buffered Clock (CP) and Output Enable (OE) inputs common to all flip-flops, ensuring synchronized data storage on the positive edge of the clock signal.

Feature Summary

• Octal D-type flip-flop architecture with separate D-type inputs for each stage
• Three-state outputs designed for bus-oriented applications
• Buffered Clock and Output Enable signals shared across all flip-flops
• TTL-compatible input thresholds for direct interfacing

Applications

• Bus-oriented data storage systems
• Microprocessor input/output port interfaces
• General-purpose register applications
• Parallel-to-serial data conversion circuits

Procurement Notes

Verify the specific suffix SJ corresponds to the 20-pin SOIC package variant when sourcing. Confirm RoHS compliance status for the specific manufacturing lot, as legacy stock may vary. Ensure the supply voltage matches the 2V to 6V operational range required for proper logic level translation and timing specifications.

Selection Notes

Select this component when an octal flip-flop with three-state outputs is required for bus sharing. The AC series offers higher speed than HC variants while maintaining CMOS power efficiency. Consider the ACT series if TTL-compatible inputs are strictly necessary without additional buffering. Verify pinout compatibility against the 74ACT374 if space constraints require alternative footprints.

Part Context

This component belongs to the 74AC logic family, representing Advanced CMOS technology. It is functionally identical to the 74ACT374 but utilizes a broadside pinout configuration. This layout places inputs and outputs on opposite sides of the package, facilitating easier routing in microprocessor interface designs compared to standard parallel layouts.

Replacement Considerations

The SN74ACT574 from Texas Instruments serves as a direct functional substitute. Other compatible alternatives include the MM74AC574MTCX and the TC74AC574AFW(TP1). Verify that replacement packages match the original footprint requirements before integration.