SN74LS243D Equivalent & Substitute Parts

Part Overview

The SN74LS243D is a non-inverting transceiver logic integrated circuit manufactured by Texas Instruments. It features 1 element with 4 bits per element and push-pull output configuration in a 14-SOIC surface mount package. The device operates within a 4.75V to 5.25V supply voltage range and is rated for 0°C to 70°C operating temperature.

The SN74LS243D carries a Last Time Buy product status, indicating that Texas Instruments has discontinued active production. This status necessitates identification of equivalent substitute components to ensure design continuity and procurement availability for new builds and ongoing production requirements.

Substiute Parts

SN74LS243D

Texas InstrumentsIn Stock: 1087SN74LS243D Datasheet

Current PartRFQ

SN74LS243DR

Texas InstrumentsIn Stock: 899SN74LS243DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SN74LS243D is determined by strict equivalence across the following critical parameters:

• Logic Type: Transceiver, Non-Inverting
• Number of Elements: 1
• Number of Bits per Element: 4
• Output Type: Push-Pull
• Current Ratings: 15mA (High), 24mA (Low)
• Supply Voltage Range: 4.75V ~ 5.25V
• Operating Temperature Range: 0°C ~ 70°C
• Package Configuration: 14-SOIC surface mount
• Compliance Standards: ROHS3, REACH Unaffected

The SN74LS243DR qualifies as a direct manufacturer-recommended substitute. Both parts share identical electrical specifications, functional characteristics, and package geometry. The primary distinction is packaging format: the SN74LS243D is supplied in Tube packaging, while the SN74LS243DR is supplied in Tape & Reel (TR) format. This difference affects procurement and assembly processes but does not alter component functionality or electrical performance.

Parameter Comparison

Engineering Selection Recommendations

The SN74LS243DR is the manufacturer-recommended substitute for the SN74LS243D. Both components are electrically and functionally identical, with full compatibility in circuit applications.

Selection between these parts should be based on procurement and assembly requirements:

• The SN74LS243D in Tube packaging is suitable for lower-volume applications, manual assembly processes, or situations where component traceability per tube is required.
• The SN74LS243DR in Tape & Reel format is optimized for high-volume automated assembly operations and provides better integration with standard pick-and-place equipment.

The SN74LS243DR carries Active product status, ensuring ongoing availability and supply chain stability. The SN74LS243D is designated Last Time Buy, indicating limited remaining inventory and no future production. For new designs or long-term production commitments, the SN74LS243DR is the preferred selection.

Both parts maintain ROHS3 compliance and REACH Unaffected status, meeting current environmental and regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS243DR be used as a direct replacement for the SN74LS243D in existing designs?

A: Yes. The SN74LS243DR is electrically and functionally identical to the SN74LS243D. No circuit modifications are required. Both components operate within the same voltage range, current specifications, and temperature range. The 14-SOIC package geometry is identical, allowing direct PCB footprint compatibility.

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

A: Tube packaging supplies components in plastic tubes, typically containing 25 to 100 units per tube, suitable for manual handling and lower-volume assembly. Tape & Reel packaging supplies components on continuous carrier tape wound on reels, optimized for automated pick-and-place assembly equipment. Both formats contain identical components with no functional differences.

Q: Why is the SN74LS243D marked as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments has ceased active production of this part number. Existing inventory may be available for a limited time, but no future manufacturing runs are planned. The SN74LS243DR, with Active status, represents the current production equivalent.

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

A: No. Both the SN74LS243D and SN74LS243DR carry identical ROHS3 compliance and REACH Unaffected status. They meet the same environmental and regulatory standards.

Q: Which part should be specified for new product designs?

A: The SN74LS243DR should be specified for new designs. Its Active product status ensures supply chain continuity and long-term availability. The SN74LS243D should only be used when existing inventory is available and design timelines do not permit transition to the substitute part.