SN74LS21NG4 Equivalent & Substitute Parts

Part Overview

The SN74LS21NG4 is a 2-channel AND gate logic IC in 14-PDIP packaging manufactured by Texas Instruments. This component is classified as discontinued at DiGi Electronics, which necessitates identification of functionally equivalent alternatives for ongoing design support and procurement. The part operates within the 74LS logic family and is suitable for digital logic applications requiring AND gate functionality with specified electrical performance characteristics.

Substiute Parts

SN74LS21NG4

Texas InstrumentsIn Stock: 892SN74LS21NG4 Datasheet

Current PartRFQ

SN74LS21N

Texas InstrumentsIn Stock: 2392SN74LS21N Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74LS21NG4 is determined by strict equivalence across the following critical parameters:

• Logic family and type (74LS AND Gate)
• Number of circuits (2) and inputs per circuit (4)
• Electrical specifications: supply voltage range (4.75V ~ 5.25V), output current ratings (400µA, 8mA), input logic levels (0.8V low, 2V high), and propagation delay (20ns @ 5V, 15pF)
• Package type and pin configuration (14-DIP through-hole)
• Operating temperature range (0°C ~ 70°C)
• Compliance certifications (ROHS3, REACH Unaffected, EAR99)

The SN74LS21N meets all substitution criteria as a direct equivalent within the same product family and base part number (74LS21).

Parameter Comparison

Engineering Selection Recommendations

The SN74LS21N is the primary substitute for the discontinued SN74LS21NG4. Both parts are manufactured by Texas Instruments and share identical electrical and mechanical specifications. The SN74LS21N maintains active product status, ensuring ongoing availability and supply chain continuity. Both parts comply with ROHS3 requirements and REACH regulations, with EAR99 export classification. The packaging difference (tube versus individual packaging) does not affect functional compatibility or pin configuration. Selection of the SN74LS21N eliminates obsolescence risk while maintaining full electrical and mechanical interchangeability.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS21N directly replace the SN74LS21NG4 in existing designs?

A: Yes. Both parts share identical logic family classification, circuit count, input configuration, electrical specifications, operating temperature range, and 14-DIP package pinout. Direct substitution is supported without circuit modification.

Q: What is the difference between the SN74LS21NG4 and SN74LS21N?

A: The primary difference is product status. The SN74LS21NG4 is discontinued at DiGi Electronics, while the SN74LS21N maintains active status. Packaging format differs (individual versus tube), but electrical and mechanical specifications are identical.

Q: Are there any compliance or certification differences?

A: No. Both parts are ROHS3 compliant, REACH unaffected, and classified as EAR99 for export purposes. Compliance certifications are equivalent.

Q: Does the 14-DIP package pinout remain the same?

A: Yes. Both parts use the 14-DIP (0.300", 7.62mm) through-hole package with identical pin configuration and spacing.

Q: What supply voltage range is supported?

A: Both parts operate within 4.75V to 5.25V supply voltage range, consistent with standard 5V logic applications.