SN75ALS191D Equivalent & Substitute Parts

Part Overview

The SN75ALS191D is a 2/0 Driver IC for RS422 and RS485 serial communication interfaces, manufactured by Texas Instruments in an 8-SOIC surface mount package. This component is classified as Last Time Buy, indicating discontinued production with limited remaining inventory. Identifying equivalent and substitute parts is essential for design continuity, long-term supply chain planning, and system reliability in applications requiring RS422/RS485 driver functionality.

Substiute Parts

SN75ALS191D

Texas InstrumentsIn Stock: 1531SN75ALS191D Datasheet

Current PartRFQ

SN75ALS191DR

Texas InstrumentsIn Stock: 1941SN75ALS191DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN75ALS191D is determined by strict equivalence across the following critical parameters:

• Protocol support: RS422 and RS485 compatibility
• Driver/Receiver configuration: 2/0 topology (2 drivers, 0 receivers)
• Electrical specifications: 4.75V to 5.25V supply voltage range
• Operating temperature range: 0°C to 70°C
• Physical package: 8-SOIC form factor with identical pin configuration
• Compliance certifications: ROHS3, REACH Unaffected status

The SN75ALS191DR qualifies as a direct substitute based on identical electrical characteristics, protocol support, and package specifications. The primary distinction is packaging format: the original part is supplied in Tube packaging, while the substitute is available in Tape & Reel (TR) format. Both parts share the same base product number (75ALS191) and maintain full functional equivalence.

Parameter Comparison

Engineering Selection Recommendations

The SN75ALS191DR is the recommended substitute for the SN75ALS191D based on the following factors:

• Active product status ensures ongoing availability and manufacturing support
• Identical electrical and functional specifications guarantee pin-for-pin compatibility
• ROHS3 compliance and REACH Unaffected status maintain regulatory alignment
• MSL Level 1 rating provides unlimited shelf life without moisture sensitivity constraints
• Tape & Reel packaging is standard for high-volume production environments and automated assembly processes

The transition from Tube to Tape & Reel packaging does not affect electrical performance or mechanical fit. This substitution is appropriate for new designs, production restocking, and long-term supply chain continuity.

Frequently Asked Questions (FAQ)

Q: Is the SN75ALS191DR a direct pin-for-pin replacement for the SN75ALS191D?

A: Yes. Both parts use the 8-SOIC package with identical pinout, electrical specifications, and functional characteristics. No circuit modifications are required.

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

A: Tube packaging is used for manual handling and small-quantity orders. Tape & Reel packaging is designed for automated pick-and-place assembly equipment and high-volume production. The electrical and mechanical properties of the component are unchanged.

Q: Can I use the SN75ALS191DR in existing designs currently using the SN75ALS191D?

A: Yes. The substitute part maintains full functional equivalence across all critical parameters: supply voltage, operating temperature, protocol support, and package dimensions.

Q: Why is the SN75ALS191D marked as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments has discontinued production of this part number. The SN75ALS191DR remains in active production and is the recommended path forward for continued supply.

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

A: No. Both parts carry identical ROHS3 compliance and REACH Unaffected status, ensuring regulatory equivalence for industrial and commercial applications.

Q: What inventory considerations should I account for when transitioning to the substitute?

A: The SN75ALS191D has 1464 units available in Tube format. The SN75ALS191DR has 1900 units available in Tape & Reel format. Tape & Reel is the preferred format for production environments and offers greater availability.