SN74LS148D Equivalent & Substitute Parts

Part Overview

The SN74LS148D is a Priority Encoder logic integrated circuit manufactured by Texas Instruments, configured as a 1 x 8:3 priority encoder in a 16-SOIC surface mount package. This component is classified as Last Time Buy, indicating limited future availability. Finding equivalent and substitute parts is necessary to ensure design continuity and supply chain reliability for applications requiring priority encoding functionality.

Substiute Parts

SN74LS148D

Texas InstrumentsIn Stock: 3111SN74LS148D Datasheet

Current PartRFQ

SN74LS148DR

Texas InstrumentsIn Stock: 23171SN74LS148DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74LS148D is determined by strict equivalence across the following critical parameters:

• Functional Configuration: Priority Encoder with 1 x 8:3 circuit topology
• Electrical Specifications: Voltage supply range 4.75V ~ 5.25V, output current ratings 400µA (high) and 8mA (low)
• Package Compatibility: 16-SOIC surface mount package with identical physical dimensions (0.154", 3.90mm width)
• Operating Temperature Range: 0°C ~ 70°C
• Compliance Standards: ROHS3 compliance and MSL Level 1 rating

The SN74LS148DR qualifies as a direct substitute based on identical electrical characteristics, functional specification, and package format. The primary distinction is packaging configuration (Tape & Reel versus Tube) and product status (Active versus Last Time Buy).

Parameter Comparison

Engineering Selection Recommendations

The SN74LS148DR is the manufacturer-recommended substitute for the SN74LS148D. Both components are manufactured by Texas Instruments and maintain identical electrical and functional specifications. The SN74LS148DR carries Active product status, ensuring continued availability and supply chain support, whereas the SN74LS148D is designated Last Time Buy.

Selection between these parts should be based on:

• Supply Continuity: The SN74LS148DR is recommended for new designs and long-term production requirements due to its Active status.
• Packaging Requirements: The SN74LS148D is supplied in Tube packaging, while the SN74LS148DR is supplied in Tape & Reel format. Packaging selection depends on assembly process requirements and order quantities.
• Compliance: Both parts meet ROHS3 compliance and carry identical MSL ratings, ensuring regulatory and environmental compatibility.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS148DR be used as a direct replacement for the SN74LS148D in existing designs?

A: Yes. The SN74LS148DR is electrically and functionally identical to the SN74LS148D. Both components feature the same 1 x 8:3 priority encoder configuration, 16-SOIC package dimensions, voltage supply specifications (4.75V ~ 5.25V), and output current ratings (400µA, 8mA). The components are pin-compatible and functionally interchangeable.

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

A: Tube packaging (SN74LS148D) is used for lower-volume orders and manual assembly processes. Tape & Reel packaging (SN74LS148DR) is designed for automated pick-and-place assembly and higher-volume production runs. The electrical and functional specifications are identical; packaging format is determined by manufacturing and assembly requirements.

Q: Why is the SN74LS148D marked as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments will discontinue production of this part number. The SN74LS148DR, with Active status, represents the recommended long-term alternative. For designs requiring continued production support and supply availability, migration to the SN74LS148DR is advised.

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

A: No. Both the SN74LS148D and SN74LS148DR are ROHS3 compliant, carry identical Moisture Sensitivity Level (MSL) ratings of 1 (Unlimited), and are REACH Unaffected. Compliance certifications and environmental ratings are equivalent.

Q: What operating temperature range is supported?

A: Both components operate across the temperature range of 0°C to 70°C, suitable for commercial and industrial applications within this thermal envelope.