SN74ALS521DWR

Comparators Overview

The SN74ALS521DWR is an 8-bit identity comparator from Texas Instruments, designed for high-speed digital logic applications. It operates within a supply voltage range of 4.5 V to 5.5 V and features open-collector outputs. The device exhibits propagation delays of 12 ns, 20 ns, and 22 ns under varying conditions. Maximum power supply current is 19 mA. It functions reliably across a temperature range of 0°C to +70°C. The component is housed in a 20-pin SOIC package and supports surface-mount installation techniques.

Comparators Feature Summary

• Provides 8-bit identity comparison functionality with enable control
• Features open-collector output structure for flexible interfacing
• Supports high-speed operation with specified propagation delays

Comparators Applications

• Digital data bus monitoring systems
• Address decoding circuits
• Data validation logic in microprocessor interfaces

Comparators Procurement Notes

Verify the specific revision level and tape-and-reel packaging configuration against project requirements. Confirm that the open-collector output type aligns with the pull-up resistor design in the target circuit. Ensure the SOIC-20 footprint matches the PCB layout specifications. Validate thermal performance within the 0°C to +70°C operating range for the intended environment.

Comparators Selection Notes

Select this component when 8-bit equality checking is required with open-collector outputs. Consider the 12 ns to 22 ns delay range for timing constraints. The ALS series offers improved speed over standard TTL while maintaining compatible voltage levels. Verify compatibility with existing system power supplies operating between 4.5 V and 5.5 V.

Comparators Part Context

This part belongs to the Texas Instruments SN74ALS family of advanced low-power Schottky logic devices. It serves as a specialized comparator variant within the broader logic IC portfolio. The DWR suffix indicates a 20-pin SOIC package with reel packaging. It complements other ALS comparators like the SN74ALS520 by providing specific identity comparison capabilities.

Comparators Replacement Considerations

The SN74ALS521DW is a non-reel version of the same functional device. Cross-reference with SN74ALS520 for octal binary/BCD identity comparison if different output structures are acceptable. Verify pinout compatibility before substitution.