54ACT521J-MSP

Overview

The 54ACT521J-MSP is an 8-bit identity comparator manufactured by National Semiconductor. It features inverted outputs that indicate equality between two 8-bit binary words. The device operates within a supply voltage range of 4.5V to 5.5V and supports a maximum propagation delay of 10ns at 5V with 50pF load. Quiescent current is typically 4µA. It is housed in a 20-pin CDIP package and is rated for operation from -55°C to 125°C.

Feature Summary

• Provides active-low output signal when two 8-bit input words are identical
• Supports high-speed digital logic operations with low quiescent power consumption
• Designed for military-grade reliability with extended temperature range capability

Applications

• Digital data comparison circuits
• Address decoding systems
• Error detection logic in military avionics

Procurement Notes

Verify the manufacturer origin, as National Semiconductor assets were acquired by Texas Instruments. Confirm the specific suffix 'MSP' corresponds to the required military grade and ceramic DIP packaging specifications. Ensure compatibility with existing 5V logic levels and check for obsolescence status before finalizing procurement plans.

Selection Notes

Select this component when an 8-bit identity comparison function is required in harsh environments. The ACT series offers faster switching speeds compared to standard TTL equivalents while maintaining compatible pinouts. Verify that the 20-pin CDIP package fits the available board space and mounting constraints.

Part Context

This part belongs to the 54ACT family of high-speed CMOS logic devices. The 54-series designation indicates military-grade qualification, distinguishing it from the commercial 74-series variants. The 521 model specifically functions as an identity comparator, providing a single output based on the equality of its inputs.

Replacement Considerations

SNJ54ALS521J is a documented alternative offering similar functionality with potentially lower power consumption.