SN74LS158NS Equivalent & Substitute Parts

Part Overview

The SN74LS158NS is a 4x2:1 multiplexer logic integrated circuit manufactured by Texas Instruments. This part is currently in Last Time Buy status, indicating it is being phased out. Finding equivalent substitute parts is necessary to ensure continued availability for new designs and ongoing production support. The SN74LS158NSR serves as the direct manufacturer-recommended substitute, offering identical functional performance with improved availability and active product status.

Substiute Parts

SN74LS158NS

Texas InstrumentsIn Stock: 1135SN74LS158NS Datasheet

Current PartRFQ

SN74LS158NSR

Texas InstrumentsIn Stock: 3208SN74LS158NSR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The SN74LS158NSR is classified as a direct manufacturer-recommended substitute based on the following substitution criteria:

• Identical functional circuit: 4x2:1 multiplexer configuration
• Same manufacturer: Texas Instruments
• Same base product number: 74LS series
• Equivalent electrical performance: Current output specifications (400µA high, 8mA low), single supply voltage operation (4.75V ~ 5.25V), and operating temperature range (0°C ~ 70°C)
• Matching compliance certifications: ROHS3 Compliant, REACH Unaffected, MSL Level 1
• Functional interchangeability in circuit applications

The primary difference is packaging format: the original part uses DIP packaging, while the substitute uses Surface Mount (16-SOIC) packaging. This distinction requires board-level design consideration but does not affect electrical substitutability when appropriate mounting infrastructure is available.

Parameter Comparison

Engineering Selection Recommendations

Selection between the SN74LS158NS and SN74LS158NSR should be based on the following factors:

For existing designs using DIP packaging: The SN74LS158NS remains available with 1051 units in current inventory. However, Last Time Buy status indicates limited future availability. Transition planning to the SN74LS158NSR is recommended for long-term production continuity.

For new designs or redesigns: The SN74LS158NSR is the preferred selection. It maintains Active product status with higher inventory levels (3111 units), ensuring sustained supply chain support. Both parts carry identical ROHS3 and REACH compliance certifications, meeting regulatory requirements without modification.

Packaging consideration: The transition from DIP (through-hole) to 16-SOIC (surface mount) requires PCB redesign. This is a one-time engineering effort that provides long-term supply security and aligns with modern manufacturing practices.

Both parts are functionally equivalent for multiplexer applications requiring 4x2:1 circuit configuration with TTL logic levels and standard operating conditions.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS158NSR directly replace the SN74LS158NS without circuit modification?

A: Electrical substitution is direct—both parts have identical functional specifications for multiplexer operation. However, packaging differs: the original uses DIP (through-hole) while the substitute uses 16-SOIC (surface mount). PCB layout and footprint changes are required.

Q: What is the significance of Last Time Buy status for the SN74LS158NS?

A: Last Time Buy indicates the manufacturer is discontinuing this product. Existing inventory will be sold until depletion, after which the part becomes unavailable. New designs should transition to the SN74LS158NSR to avoid future supply constraints.

Q: Are there compliance differences between these parts?

A: No. Both parts carry identical certifications: ROHS3 Compliant, REACH Unaffected, and MSL Level 1 (Unlimited). Regulatory requirements are met by either part.

Q: What are the electrical operating parameters for these multiplexers?

A: Both parts operate with single supply voltage (4.75V ~ 5.25V), output current specifications of 400µA high and 8mA low, and operating temperature range of 0°C ~ 70°C. These parameters define the 74LS series logic family.

Q: Is the SN74LS158NSR suitable for high-volume production?

A: Yes. The SN74LS158NSR has Active product status with 3111 units in current inventory, indicating stable supply chain support suitable for production quantities. Surface mount packaging also aligns with automated assembly processes.

Q: What is the base product number for these parts?

A: Both parts share the base product number 74LS158, identifying the functional circuit type (4x2:1 multiplexer). The suffix designates packaging and lead configuration.