SN74LS259BNSR Equivalent & Substitute Parts

Part Overview

The SN74LS259BNSR is an 8-bit addressable latch IC manufactured by Texas Instruments, classified as a D-Type, Addressable logic component with a 1:8 circuit configuration. This device is designated as Obsolete, which necessitates identification of functionally equivalent alternatives for ongoing design requirements and production continuity. The part operates within a 4.75V to 5.25V supply voltage range and is housed in a 16-SOIC package measuring 5.30mm in width.

Substiute Parts

SN74LS259BNSR

Texas InstrumentsIn Stock: 1178SN74LS259BNSR Datasheet

Current PartRFQ

SN74LS259BD

Texas InstrumentsIn Stock: 1548SN74LS259BD Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SN74LS259BNSR is determined by strict equivalence across the following critical parameters:

Logic Type and Circuit Configuration: The substitute must maintain D-Type, Addressable logic architecture with 1:8 circuit configuration and Standard output type.

Electrical Performance: Supply voltage range (4.75V ~ 5.25V), propagation delay (19ns), and output current specifications (400µA, 8mA) must be identical.

Physical and Environmental Compliance: Operating temperature range (0°C ~ 70°C), RoHS3 compliance, MSL rating (1), and REACH status must match.

Mounting and Package Compatibility: Surface mount technology with 16-SOIC package footprint is required. Package width variations within the 16-SOIC family are permissible when PCB layout accommodates the dimensional difference.

The SN74LS259BD qualifies as a direct substitute based on full alignment with these parameters, with the distinction that it is classified as Last Time Buy rather than Obsolete, and features a 16-SOIC package with 3.90mm width compared to the 5.30mm width of the original part.

Parameter Comparison

Engineering Selection Recommendations

The SN74LS259BD is the qualified substitute for the SN74LS259BNSR based on complete electrical and functional equivalence. Both parts maintain identical logic architecture, electrical specifications, and environmental compliance ratings. The primary distinction is product lifecycle status: the original part is Obsolete, while the substitute is designated Last Time Buy, indicating continued but limited availability.

The package width differential (5.30mm versus 3.90mm) represents a physical variation within the 16-SOIC family. PCB layout verification is necessary to confirm that the narrower package footprint of the SN74LS259BD accommodates existing design constraints. Both parts carry ROHS3 compliance and unlimited moisture sensitivity ratings, ensuring regulatory and environmental compatibility.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS259BD be used as a direct replacement for the SN74LS259BNSR in existing designs?

A: Yes, the SN74LS259BD is electrically and functionally equivalent. Verification of PCB layout compatibility is required due to the 16-SOIC package width difference (3.90mm versus 5.30mm).

Q: What is the significance of the product status change from Obsolete to Last Time Buy?

A: Obsolete status indicates the part is no longer manufactured or supported. Last Time Buy status indicates the substitute has limited remaining availability before discontinuation. Both statuses necessitate long-term supply planning.

Q: Are the electrical performance characteristics identical between the main part and substitute?

A: Yes. Supply voltage range, propagation delay, output current specifications, and operating temperature range are identical across both parts.

Q: Do both parts meet the same compliance and regulatory requirements?

A: Yes. Both parts are ROHS3 compliant, REACH unaffected, and carry MSL rating 1 (Unlimited), ensuring equivalent regulatory and environmental compliance.

Q: What packaging consideration should be evaluated for the SN74LS259BD?

A: The SN74LS259BD uses a 16-SOIC package with 3.90mm width, compared to the 5.30mm width of the original part. PCB footprint and layout spacing must be verified for compatibility with existing designs.