SN74ALS259D Equivalent & Substitute Parts

Part Overview

The SN74ALS259D is an 8-bit addressable latch IC manufactured by Texas Instruments, designed for digital logic applications requiring address-selectable data storage. This component features D-type, addressable architecture with a 1:8 circuit configuration and operates within the 4.5V to 5.5V supply voltage range. The part is currently in Last Time Buy status, indicating discontinued production with limited inventory availability. Identifying qualified substitute parts ensures design continuity and supply chain reliability for ongoing production and maintenance applications.

Substiute Parts

SN74ALS259D

Texas InstrumentsIn Stock: 1192SN74ALS259D Datasheet

Current PartRFQ

SN74ALS259DR

Texas InstrumentsIn Stock: 1053SN74ALS259DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SN74ALS259D is determined by strict equivalence across the following critical parameters:

• Logic Architecture: D-Type, Addressable configuration with 1:8 circuit topology
• Electrical Performance: 4.5V to 5.5V supply voltage, 2ns propagation delay, 400µA/8mA output current specifications
• Package Compatibility: 16-SOIC surface mount package with identical 0.154" (3.90mm) width
• Thermal Range: 0°C to 70°C operating temperature
• Compliance Standards: ROHS3 compliance and MSL Level 1 rating

The SN74ALS259DR qualifies as a direct substitute based on identical electrical characteristics, package geometry, and compliance certifications. The primary distinction is packaging format: the main part uses Tube packaging while the substitute uses Tape & Reel (TR) format. Both parts share the same base product number (74ALS259) and are manufactured by Texas Instruments.

Parameter Comparison

Engineering Selection Recommendations

The SN74ALS259DR is a qualified direct substitute for the SN74ALS259D based on complete electrical and mechanical equivalence. Both parts maintain identical functional specifications, thermal operating range, and compliance certifications (ROHS3, MSL Level 1).

The primary consideration for part selection is product status and supply availability. The SN74ALS259D is designated Last Time Buy, indicating production discontinuation with finite inventory. The SN74ALS259DR maintains Active status with ongoing manufacturing support, making it the preferred choice for new designs and long-term supply chain planning.

The packaging format difference (Tube versus Tape & Reel) does not affect electrical performance or PCB assembly compatibility. Selection between these formats depends on procurement volume and assembly process requirements. Tape & Reel packaging is standard for automated pick-and-place assembly operations, while Tube packaging is suitable for lower-volume manual assembly or component stocking applications.

Frequently Asked Questions (FAQ)

Q: Can the SN74ALS259DR be used as a direct replacement for the SN74ALS259D in existing designs?

A: Yes. Both parts are electrically and mechanically equivalent. They share identical logic architecture, electrical performance specifications, operating temperature range, and 16-SOIC package geometry. No design modifications are required for substitution.

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

A: Tube packaging contains loose components in a plastic tube, suitable for manual handling and lower-volume applications. Tape & Reel packaging places components on a continuous carrier tape wound on a reel, optimized for automated assembly equipment. Both formats contain the same component with identical electrical characteristics.

Q: Why is the SN74ALS259D marked as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments has discontinued production of this part number. Existing inventory is available for purchase, but no future manufacturing runs are planned. The SN74ALS259DR, with Active status, represents the current production equivalent.

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

A: No. Both parts maintain identical ROHS3 compliance and MSL Level 1 ratings. They are equivalent for applications requiring these certifications.

Q: What supply voltage range does this component support?

A: Both the SN74ALS259D and SN74ALS259DR operate within a 4.5V to 5.5V supply voltage range, standard for TTL-compatible logic circuits.

Q: What is the propagation delay specification?

A: Both parts specify a 2ns propagation delay, ensuring consistent timing performance in address-selectable latch applications.