SN74ALS191AD Binary Counter IC Equivalent & Substitute Parts

Part Overview

The SN74ALS191AD is a 4-bit binary counter IC manufactured by Texas Instruments, designed for synchronous up/down counting applications. This component operates at a maximum count rate of 30 MHz with a supply voltage range of 4.5 V to 5.5 V and is housed in a 16-SOIC surface mount package. The SN74ALS191AD is currently in Last Time Buy status, making identification of functionally equivalent alternatives essential for ongoing design support and procurement planning.

Substiute Parts

SN74ALS191AD

Texas InstrumentsIn Stock: 1260SN74ALS191AD Datasheet

Current PartRFQ

SN74ALS191ADR

Texas InstrumentsIn Stock: 934SN74ALS191ADR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74ALS191AD is determined by strict equivalence across the following critical parameters:

• Logic Function: Binary counter with identical 4-bit architecture and up/down counting capability
• Electrical Performance: Synchronous timing, 30 MHz count rate, positive edge trigger, and 4.5 V to 5.5 V supply voltage range
• Package Compatibility: 16-SOIC surface mount package with identical pin configuration and mechanical dimensions
• Environmental Compliance: ROHS3 compliance and MSL Level 1 rating
• Thermal Range: 0°C to 70°C operating temperature specification

The SN74ALS191ADR qualifies as a direct substitute based on identical electrical specifications and package configuration. The only distinction is packaging format: the main part is supplied in Tube packaging, while the substitute is supplied in Tape & Reel format.

Parameter Comparison

Engineering Selection Recommendations

The SN74ALS191ADR is a direct functional and electrical equivalent to the SN74ALS191AD. Both components are manufactured by Texas Instruments and maintain identical electrical specifications, pin configurations, and package dimensions. The SN74ALS191ADR is recommended for new designs and ongoing procurement due to its Active product status, whereas the SN74ALS191AD is in Last Time Buy status.

The primary distinction between these parts is packaging format. The SN74ALS191AD is supplied in Tube packaging, suitable for lower-volume applications and manual assembly processes. The SN74ALS191ADR is supplied in Tape & Reel format, optimized for automated pick-and-place assembly and higher-volume production environments.

Both parts maintain ROHS3 compliance and are suitable for applications requiring synchronous 4-bit binary counting with up/down capability at frequencies up to 30 MHz within the 4.5 V to 5.5 V supply range.

Frequently Asked Questions (FAQ)

Q: Can the SN74ALS191ADR be used as a direct replacement for the SN74ALS191AD in existing designs?

A: Yes. The SN74ALS191ADR is electrically and functionally identical to the SN74ALS191AD. Both components share the same pin configuration, electrical specifications, and 16-SOIC package dimensions. No circuit modifications are required for substitution.

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

A: Tube packaging supplies components in plastic tubes, typically used for manual assembly and lower-volume applications. Tape & Reel packaging supplies components on continuous carrier tape wound on reels, optimized for automated assembly equipment. Both formats contain identical components with no electrical differences.

Q: Why is the SN74ALS191AD listed as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments is discontinuing this part number. Existing inventory may be available for a limited time, but new orders should transition to the SN74ALS191ADR, which maintains Active status and ensures long-term availability.

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

A: No. Both the SN74ALS191AD and SN74ALS191ADR maintain identical ROHS3 compliance, MSL Level 1 rating, and REACH Unaffected status. Environmental and regulatory certifications are equivalent.

Q: What is the maximum count rate for both parts?

A: Both the SN74ALS191AD and SN74ALS191ADR support a maximum count rate of 30 MHz under the specified supply voltage range of 4.5 V to 5.5 V and operating temperature range of 0°C to 70°C.