SN74AS08D Equivalent & Substitute Parts

Part Overview

The SN74AS08D is a 4-channel 2-input AND gate logic IC manufactured by Texas Instruments in 14-SOIC surface mount packaging. This component is classified as Last Time Buy, indicating discontinued production with limited remaining inventory. The identification of equivalent and substitute parts is necessary to ensure design continuity and procurement flexibility for applications requiring AND gate functionality with identical electrical and mechanical specifications.

Substiute Parts

SN74AS08D

Texas InstrumentsIn Stock: 1664SN74AS08D Datasheet

Current PartRFQ

SN74AS08DR

Texas InstrumentsIn Stock: 2689SN74AS08DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74AS08D is determined by strict equivalence across the following critical parameters:

• Logic function: 4-channel 2-input AND gate
• Electrical specifications: 4.5V ~ 5.5V supply voltage, 2mA/20mA output current, 0.8V/2V input logic levels, 5.5ns propagation delay
• Mechanical compatibility: 14-SOIC surface mount package with identical 0.154" (3.90mm) width
• Compliance: ROHS3 compliance and MSL Level 1 rating

The SN74AS08DR qualifies as a direct substitute based on identical electrical performance, package geometry, and compliance certifications. The primary distinction is packaging format: the main part is supplied in Tube packaging, while the substitute is supplied in Cut Tape (CT) format. Both parts share the same base product number (74AS08) and maintain full functional and mechanical interchangeability.

Parameter Comparison

Engineering Selection Recommendations

The SN74AS08DR is the qualified substitute for the SN74AS08D based on product status and compliance alignment. The main part is designated Last Time Buy with 1585 units in stock, while the substitute maintains Active status with 2598 units available. Both parts carry identical ROHS3 compliance and REACH Unaffected status, ensuring regulatory continuity.

Selection between these parts should be driven by procurement requirements and packaging format compatibility. The Tube packaging of the main part suits high-volume automated assembly, while the Cut Tape format of the substitute accommodates pick-and-place operations and lower-volume requirements. No electrical or mechanical redesign is required when transitioning between these parts.

Frequently Asked Questions (FAQ)

Q: Can the SN74AS08DR replace the SN74AS08D in existing designs?

A: Yes. Both parts are electrically and mechanically identical. The SN74AS08DR operates at the same supply voltage (4.5V ~ 5.5V), delivers identical output current (2mA/20mA), maintains the same input logic levels (0.8V/2V), and exhibits the same propagation delay (5.5ns @ 5V, 50pF). The 14-SOIC package dimensions are identical, enabling direct PCB compatibility without layout modifications.

Q: What is the difference between Tube and Cut Tape packaging?

A: Tube packaging supplies components in plastic tubes suitable for high-speed automated pick-and-place assembly. Cut Tape packaging provides components on carrier tape with individual component spacing, typically used for lower-volume production or manual assembly. Both formats contain identical components with no functional differences.

Q: Are there compliance differences between these parts?

A: No. Both the SN74AS08D and SN74AS08DR carry identical ROHS3 compliance, REACH Unaffected status, and Moisture Sensitivity Level 1 (Unlimited) ratings. No compliance re-qualification is required when substituting between these parts.

Q: Why is the SN74AS08D marked as Last Time Buy?

A: Last Time Buy designation indicates Texas Instruments has discontinued production of this part number. The SN74AS08DR, with Active product status, represents the current production equivalent and should be considered for new designs and long-term procurement planning.

Q: Are the propagation delay specifications identical?

A: Yes. Both parts specify 5.5ns maximum propagation delay at 5V with 50pF load, ensuring identical timing performance in logic circuits.