74FCT574SC

Overview

The National Semiconductor 74FCT574SC is an octal edge-triggered D-type flip-flop featuring three-state outputs, designed for high-speed digital logic applications. It operates within a supply voltage range of 4.75 V to 5.25 V and supports TTL-compatible inputs. The device utilizes CMOS technology and is housed in a 20-pin DIP package. Key electrical characteristics include a propagation delay of 6.5 ns at 50 pF load, with output drive capabilities of -15 mA (high) and 48 mA (low). It functions reliably across an industrial temperature range of -40°C to +85°C.

Feature Summary

• Octal configuration providing eight independent D-type flip-flops with positive-edge triggering.

Applications

• High-speed data register storage in digital systems
• Bus interface circuits requiring three-state isolation
• Parallel-to-serial conversion modules

Procurement Notes

Verify the manufacturer designation carefully, as National Semiconductor's logic assets were acquired by Texas Instruments. Confirm that the specific 'NS' prefix part number aligns with current inventory sources or identify equivalent TI-branded variants. Ensure the package type matches the required PCB footprint and check for RoHS compliance status relative to the production era.

Selection Notes

Select this component when an octal register with three-state outputs is required for bus-oriented architectures. The FCT series offers speed comparable to LS-TTL but with lower power consumption typical of CMOS. Consider the 20-pin DIP package constraints for through-hole assembly versus surface-mount alternatives if space is limited.

Part Context

This component belongs to the Fairchild/NS 74FCT logic family, which bridges the performance gap between standard TTL and advanced CMOS technologies. The 74FCT574 specifically serves as an octal D-type flip-flop, widely used in legacy computing and industrial control systems where high-speed latching and bus driving are necessary.

Replacement Considerations

• SN74FCT574SC (Texas Instruments)
• CY74FCT574SC (Cypress)