SN74LS688NG4 Equivalent & Substitute Parts

Part Overview

The SN74LS688NG4 is an 8-bit identity/magnitude comparator manufactured by Texas Instruments, designed for logic-level comparison applications. This device features active-low output with A=B output function, operating within the 4.85V to 5.25V supply voltage range. The part is discontinued at DiGi Electronics, making equivalent substitutes necessary for ongoing design requirements and component sourcing.

Substiute Parts

SN74LS688NG4

Texas InstrumentsIn Stock: 869SN74LS688NG4 Datasheet

Current PartRFQ

SN74LS688N

Texas InstrumentsIn Stock: 3112SN74LS688N Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the SN74LS688NG4 is determined by the following critical parameters:

• Base Product Number: 74LS688 (core logic function)
• Number of Bits: 8-bit comparison capability
• Output Configuration: Active-low output with A=B function
• Supply Voltage Range: 4.85V ~ 5.25V compatibility
• Package Type: 20-DIP through-hole mounting
• Electrical Performance: Propagation delay and output current specifications

The SN74LS688N qualifies as a direct substitute based on identical base product number, bit configuration, output function, and electrical characteristics. Both devices implement the same 8-bit identity comparator logic with active-low output, ensuring functional equivalence in circuit applications.

Parameter Comparison

Engineering Selection Recommendations

The SN74LS688N is the primary substitute for the discontinued SN74LS688NG4. Both devices share identical base product designation and core functional specifications. The SN74LS688N maintains active product status with higher inventory availability (3035 pcs), ensuring reliable sourcing for replacement and new designs.

Selection between these parts should be based on:

• Product Availability: SN74LS688N is actively manufactured and stocked
• Compliance Requirements: Both devices maintain REACH Unaffected status
• Functional Equivalence: Identical 8-bit identity comparator operation with active-low A=B output
• Supply Voltage Compatibility: Both operate within 4.85V ~ 5.25V range

Frequently Asked Questions (FAQ)

Q: Can the SN74LS688N directly replace the SN74LS688NG4 in existing designs?

A: Yes. Both devices implement identical 8-bit identity comparator logic with active-low output. The functional specifications, electrical characteristics, and pin configuration are equivalent, enabling direct substitution in circuit applications.

Q: What is the significance of the "NG4" and "N" suffixes in these part numbers?

A: The suffix designates packaging and lead finish specifications. Both variants contain the same core logic die and functional performance. The difference lies in packaging details and manufacturing date codes, not in electrical operation.

Q: Are there any compliance or regulatory differences between these parts?

A: No. Both the SN74LS688NG4 and SN74LS688N maintain REACH Unaffected status and are ROHS3 compliant, ensuring equivalent regulatory compliance for industrial and commercial applications.

Q: What should be considered when sourcing the SN74LS688N as a replacement?

A: Verify that the substitute part meets your specific supply voltage requirements (4.85V ~ 5.25V), operating temperature range (0°C ~ 70°C), and through-hole 20-DIP package compatibility. Confirm inventory availability with your component supplier, as the SN74LS688N is actively produced with higher stock levels than the discontinued variant.

Q: Is the 20-DIP package format critical for substitution?

A: Yes. The 20-DIP through-hole package is a fundamental requirement for direct substitution. Both the main part and substitute maintain this identical package specification, ensuring PCB compatibility without redesign.