SN74LS684NS

Overview

The SN74LS684NS is an 8-bit magnitude and identity comparator manufactured by Texas Instruments. It operates within a supply voltage range of 4.85 V to 5.25 V and supports propagation delays of 25 ns and 30 ns. The device features totem-pole outputs and draws a maximum supply current of 70 mA. Designed for surface mount applications, it is housed in a 20-pin SOIC package. The component functions reliably across an operating temperature range from 0°C to +70°C.

Feature Summary

• Performs 8-bit magnitude comparison operations
• Provides identity detection capabilities
• Utilizes totem-pole output structure

Applications

• Programmable Logic Controller (PLC) systems
• Human Machine Interface (HMI) devices
• Industrial equipment control circuits
• Machine vision processing units

Procurement Notes

Verify the specific suffix NS indicates the SOIC-20 surface mount package configuration distinct from through-hole variants. Confirm the logic family designation LS aligns with required power consumption and speed specifications for the target design. Ensure the commercial temperature grade meets environmental constraints. Cross-reference the manufacturer part number against official distributor catalogs to validate authenticity and current production status before finalizing procurement orders.

Selection Notes

Select this component when 8-bit parallel data comparison is required in space-constrained designs. The SOIC-20 package facilitates automated surface mount assembly processes. Consider the 70 mA maximum supply current for adequate power distribution planning. Verify that the 25 ns to 30 ns propagation delay satisfies the timing requirements of the system clock. Ensure compatibility with standard 5V logic levels used in industrial control environments.

Part Context

This comparator belongs to the Texas Instruments SN74LS series, which utilizes Low-power Schottky technology. The series provides improved switching speeds compared to standard TTL while maintaining lower power dissipation. The SN74LS684NS represents a specialized function within this family, dedicated to digital magnitude evaluation rather than general logic gating or memory storage functions.

Replacement Considerations

Check for SN74LS684N as a potential PDIP alternative if through-hole mounting is required. Verify pinout compatibility and electrical characteristics match exactly before substituting. Consult official replacement guides for any updated revisions or end-of-life notices affecting availability.