SN74LS08N-NG Equivalent & Substitute Parts

Part Overview

The SN74LS08N-NG is a 4-channel 2-input AND Gate logic integrated circuit manufactured by Texas Instruments in the 74LS series. This device implements four independent AND gates with 2-input configurations in a 14-pin DIP package. The product is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing design support, maintenance, and new production applications where modern component availability is required.

Substiute Parts

SN74LS08N-NG

Texas InstrumentsIn Stock: 1026SN74LS08N-NG Datasheet

Current PartRFQ

SN74AC08PWR

Texas InstrumentsIn Stock: 81694SN74AC08PWR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74LS08N-NG is determined by the following critical parameters:

Functional Equivalence Requirements:

• Logic Type: AND Gate (4 channels, 2 inputs per channel)
• Number of Circuits: 4
• Number of Inputs: 2

Electrical Compatibility Parameters:

• Supply Voltage Range: Must accommodate 5V nominal operation
• Input Logic Levels: Must be compatible with standard TTL/CMOS logic levels
• Output Drive Capability: Must support required load currents

Physical and Environmental Constraints:

• Package configuration and pin count must match or be compatible with board layout
• Operating temperature range must meet application requirements
• RoHS compliance status must satisfy regulatory requirements

The SN74AC08PWR qualifies as a substitute based on identical logic function (4-channel 2-input AND gate), compatible supply voltage operation at 5V, and ROHS3 compliance. However, differences in packaging (Surface Mount vs. Through Hole), operating temperature range, and electrical characteristics require engineering evaluation for specific applications.

Parameter Comparison

Engineering Selection Recommendations

SN74AC08PWR as Substitute:

The SN74AC08PWR is an active product from Texas Instruments that performs the identical logic function as the obsolete SN74LS08N-NG. Both devices implement 4-channel 2-input AND gate logic and are ROHS3 compliant.

Key Considerations:

1. Packaging Transition: The SN74AC08PWR uses Surface Mount (14-TSSOP) packaging versus the Through Hole (14-DIP) of the original part. This requires PCB redesign if direct socket replacement is required.

2. Electrical Performance: The SN74AC08PWR operates across a wider supply voltage range (2V ~ 6V) compared to the SN74LS08N-NG (4.75V ~ 5.25V), providing greater design flexibility. Propagation delay is significantly faster (7.5ns vs. 20ns at 5V), and quiescent current is substantially lower (2µA vs. 8.8mA).

3. Temperature Range: The SN74AC08PWR supports -40°C ~ 85°C operation, exceeding the original part's 0°C ~ 70°C range.

4. Product Availability: The SN74AC08PWR is in active production with substantial inventory availability (81,645 pieces), ensuring long-term supply continuity.

5. Compliance Status: Both parts maintain ROHS3 compliance, satisfying regulatory requirements for new designs and production.

Frequently Asked Questions (FAQ)

Q: Can the SN74AC08PWR directly replace the SN74LS08N-NG in existing through-hole PCB designs?

A: No. The SN74AC08PWR uses Surface Mount (14-TSSOP) packaging while the SN74LS08N-NG uses Through Hole (14-DIP) packaging. Direct socket replacement is not possible. PCB redesign or use of an adapter carrier would be required.

Q: Are the logic functions identical between these two parts?

A: Yes. Both devices implement 4-channel 2-input AND gate logic with identical pin functionality and truth table behavior.

Q: What are the supply voltage compatibility differences?

A: The SN74LS08N-NG operates at 4.75V ~ 5.25V (5V nominal). The SN74AC08PWR operates at 2V ~ 6V. At 5V operation, both parts are electrically compatible. The SN74AC08PWR provides additional flexibility for lower voltage applications.

Q: How do the propagation delays compare?

A: The SN74AC08PWR has a maximum propagation delay of 7.5ns at 5V with 50pF load, compared to 20ns for the SN74LS08N-NG at 5V with 15pF load. The SN74AC08PWR is faster and supports higher capacitive loads.

Q: Is the SN74AC08PWR suitable for low-power applications?

A: Yes. The SN74AC08PWR has significantly lower quiescent current (2µA) compared to the SN74LS08N-NG (8.8mA), making it more suitable for power-constrained applications.

Q: Are both parts RoHS compliant?

A: Yes. Both the SN74LS08N-NG and SN74AC08PWR are ROHS3 compliant.

Q: What is the moisture sensitivity level of the SN74AC08PWR?

A: The SN74AC08PWR has a Moisture Sensitivity Level (MSL) of 1 (Unlimited), indicating no moisture sensitivity restrictions for storage and handling.