7491ADC

Overview

The 7491ADC is an 8-bit shift register integrated circuit manufactured by National Semiconductor, designed for use with Transistor-Transistor Logic (TTL) circuits. It features a parallel load input and operates within a temperature range of 0°C to 70°C. The component utilizes a 14-pin Ceramic Dual In-Line Package (CDIP) with a pin spacing of 0.300 inches, suitable for through-hole mounting.

Feature Summary

• Supports synchronous operation via dedicated clock input and output pins
• Enables data manipulation through a parallel load input mechanism
• Compatible with standard TTL logic families for digital signal processing

Applications

• Digital data storage and transfer systems
• Synchronous control circuits requiring bit shifting
• Parallel-to-serial or serial-to-parallel conversion interfaces

Procurement Notes

Verify the manufacturer designation as National Semiconductor, now part of Texas Instruments, to ensure authenticity. Confirm the package type is 14-CDIP and the operating temperature range matches the specified industrial limits. Check for any specific ordering suffixes that may indicate variant differences, ensuring the selected part aligns precisely with the required electrical characteristics and physical form factor.

Selection Notes

Select this component when an 8-bit TTL-compatible shift register with parallel loading capabilities is required. Ensure the design supports through-hole assembly due to the CDIP package. Verify that the system voltage levels are compatible with standard TTL inputs and outputs. Consider the thermal environment to ensure operation remains within the 0°C to 70°C range for reliable performance.

Part Context

This component belongs to the 7491 series of shift registers, a legacy line of logic devices widely used in older digital systems. National Semiconductor produced these ICs before its acquisition by Texas Instruments. The 7491ADC specifically denotes the ceramic dual in-line package variant, offering robustness for applications where plastic packages might be less suitable.

Replacement Considerations

Cross-reference with other 8-bit TTL shift registers from the same logic family. Verify pin compatibility and logical functionality before substituting. Ensure the replacement maintains the parallel load feature and synchronous clocking requirements.