74ACT521SCX

Overview

The onsemi 74ACT521SCX is an 8-bit identity comparator integrated circuit belonging to the 74ACT logic series. It operates within a supply voltage range of 4.5V to 5.5V and features active-low outputs that indicate equality between two 8-bit inputs. The device provides high drive capability with output currents of 24mA for both high and low states, while maintaining a low quiescent current of 4µA. It exhibits a maximum propagation delay of 10ns at 5V with a 50pF load. Packaged in a 20-SOIC surface-mount case, it supports an operating temperature range from -40°C to +85°C.

Feature Summary

• Provides magnitude comparison functionality with active-low output indicating input equality
• Delivers strong output drive capability suitable for direct interfacing with TTL or CMOS loads
• Ensures fast signal processing through low propagation delay characteristics typical of ACT technology

Applications

• Digital data bus monitoring systems requiring equality verification
• Address decoding circuits in microprocessor-based architectures
• Error detection logic in digital communication interfaces

Procurement Notes

Verify component authenticity by checking manufacturer markings against official datasheet specifications. Confirm package dimensions match the 20-SOIC standard. Ensure the part number suffix aligns with required tape-and-reel packaging if applicable. Validate electrical parameters against the specific lot documentation provided by the supplier to guarantee compliance with operational requirements.

Selection Notes

Select this component when an 8-bit identity comparison function is required within the 74ACT logic family constraints. Consider the 20-SOIC package for surface-mount assembly needs. Evaluate the 4.5V to 5.5V supply requirement against system power rails. Assess the 24mA output drive strength against downstream load requirements to ensure signal integrity without additional buffering.

Part Context

This part belongs to the 74ACT series of high-speed CMOS logic devices manufactured by onsemi. The 74ACT521 specifically functions as an 8-bit identity comparator. It shares the same logical functionality as the 74AC521 but offers improved switching speeds and noise immunity characteristic of the ACT sub-family. The SCX suffix denotes the tube or reel packaging variant within the SOIC-20 form factor.

Replacement Considerations

The 74ACT521SC is the tube-packaged equivalent of this reel-part. Cross-reference with other 74ACT521 variants from different manufacturers ensuring pin compatibility and electrical parameter alignment.