JD54LS74SCA

Flip Flops Overview

The SN54LS74SCA is a dual D-type flip-flop manufactured by National Semiconductor, now part of Texas Instruments. It operates within the LS-TTL logic family and features individual data (D), clock (CLK), preset, and clear inputs for each flip-flop. The device provides complementary outputs (Q and Q-bar). It is housed in a 14-lead ceramic flatpack package with a pin pitch of 2.54 mm. The component requires a nominal 5 V supply voltage and supports commercial temperature operation.

Flip Flops Feature Summary

• Dual independent D-type flip-flops with complementary outputs
• Asynchronous preset and clear control inputs
• Negative-edge-triggered data transfer on clock pulse
• Ceramic flatpack construction for high reliability

Flip Flops Applications

• Parallel-to-serial data conversion circuits
• Shift register stage implementation
• Digital state storage and memory elements
• Timing sequence control logic

Flip Flops Procurement Notes

Verify that the specific suffix 'SCA' corresponds to the ceramic flatpack variant with the correct lead configuration. Confirm RoHS compliance status as older LS-TTL parts may contain lead. Ensure the supplier provides traceability to National Semiconductor or Texas Instruments official documentation. Check for military-grade environmental screening if the '54' prefix implies extended specifications beyond standard commercial limits.

Flip Flops Selection Notes

Select this component when dual isolated D-latches are required in a high-reliability environment. The ceramic flatpack offers superior thermal and mechanical stability compared to plastic packages. Verify that the circuit design accommodates the LS-TTL input/output voltage levels and current requirements. Ensure the PCB footprint matches the specific dimensions of the 14-lead ceramic flatpack housing.

Flip Flops Part Context

This part belongs to the SN54/74LS series of low-power Schottky TTL logic devices. The '54' prefix typically denotes military-grade temperature and performance specifications, while '74' indicates commercial grade. National Semiconductor was acquired by Texas Instruments, which continues to support legacy logic families. The LS series balances power consumption with speed for general digital applications.

Flip Flops Replacement Considerations

SN54LS74FC

Flip Flops FAQ

What is the trigger mechanism for the data input?

The flip-flops are negative-edge-triggered, meaning data is transferred from the D input to the Q output on the falling edge of the clock signal.

Does the device include asynchronous controls?

Yes, each flip-flop has dedicated asynchronous preset and clear inputs that operate independently of the clock signal.