SN74LS191DE4 Equivalent & Substitute Parts

Part Overview

The SN74LS191DE4 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 25 MHz with positive edge triggering and is housed in a 16-SOIC surface mount package. The part is currently in Last Time Buy status, indicating discontinued production. Identifying equivalent and substitute parts is necessary to ensure design continuity and maintain supply chain reliability for existing applications and new designs requiring this functionality.

Substiute Parts

SN74LS191DE4

Texas InstrumentsIn Stock: 723SN74LS191DE4 Datasheet

Current PartRFQ

SN74LS191D

Texas InstrumentsIn Stock: 1533SN74LS191D Datasheet

MFR RecommendedRFQ

SN74LS191DR

Texas InstrumentsIn Stock: 4495SN74LS191DR Datasheet

MFR RecommendedRFQ

SN74LS169BD

Texas InstrumentsIn Stock: 1177SN74LS169BD Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the SN74LS191DE4 is determined by strict equivalence across the following critical parameters: logic type (binary counter), bit width (4-bit), counting direction (up/down), timing architecture (synchronous), count rate capability (25 MHz minimum), trigger mechanism (positive edge), supply voltage range (4.75 V ~ 5.25 V), operating temperature range (0°C ~ 70°C), and physical package specification (16-SOIC).

Substitute parts are grouped into two categories:

MFR Recommended Substitutes: Parts that maintain identical electrical and mechanical specifications with the main part, differing only in packaging format or product status.

Parametric Equivalents: Parts that satisfy all critical electrical parameters and package requirements but may have different base product designations while maintaining functional compatibility.

Parameter Comparison

Engineering Selection Recommendations

SN74LS191D: This part is recommended as the primary substitute for the SN74LS191DE4. It maintains identical electrical specifications and 16-SOIC package configuration. The difference lies in packaging format (Tube vs. standard supply). Both parts carry Last Time Buy status, indicating similar lifecycle positioning. This substitute is suitable for direct replacement in existing designs.

SN74LS191DR: This part is recommended for new designs and applications requiring active product status. It provides identical electrical and mechanical specifications to the SN74LS191DE4 but is supplied in Cut Tape (CT) & Digi-Reel® format. The Active product status ensures continued availability and manufacturing support. This substitute is optimal for high-volume production environments.

SN74LS169BD: This part qualifies as a parametric equivalent, satisfying all critical electrical parameters and package requirements. It differs in base product designation (74LS169 vs. 74LS191) but maintains functional compatibility for 4-bit synchronous up/down counting applications. This part carries Active product status. Selection of this substitute should be validated against specific application requirements and pinout compatibility.

All substitute parts maintain ROHS3 compliance, MSL Level 1 rating, and identical supply voltage and operating temperature specifications, ensuring compliance with environmental and reliability standards.

Frequently Asked Questions (FAQ)

Q: Can SN74LS191D be used as a direct replacement for SN74LS191DE4?

A: Yes. Both parts are electrically and mechanically identical, with the same 16-SOIC package, electrical specifications, and functional characteristics. The difference is packaging format. Direct substitution is supported.

Q: What is the advantage of using SN74LS191DR over SN74LS191DE4?

A: SN74LS191DR maintains identical electrical and package specifications but carries Active product status, ensuring continued manufacturing support and availability. It is supplied in Cut Tape & Digi-Reel® format, which is preferred for automated assembly and high-volume production.

Q: Is SN74LS169BD compatible with designs using SN74LS191DE4?

A: SN74LS169BD satisfies all critical electrical parameters: 4-bit binary counter, synchronous timing, up/down direction, 25 MHz count rate, positive edge triggering, and identical supply voltage and operating temperature ranges. However, it carries a different base product designation. Pinout and functional compatibility must be verified against specific application requirements before implementation.

Q: Why are some substitutes in Last Time Buy status while others are Active?

A: Product status reflects manufacturing lifecycle. Last Time Buy indicates discontinued production with limited remaining inventory. Active status indicates ongoing production and supply availability. For new designs, Active status parts (SN74LS191DR, SN74LS169BD) are preferred to ensure long-term supply chain reliability.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed parts—SN74LS191DE4, SN74LS191D, SN74LS191DR, and SN74LS169BD—are ROHS3 compliant with MSL Level 1 rating, meeting environmental and reliability standards.

Q: What packaging formats are available for these substitutes?

A: SN74LS191DE4 and SN74LS191D are supplied in Tube packaging. SN74LS191DR is supplied in Cut Tape (CT) & Digi-Reel® format. SN74LS169BD is supplied in Tube packaging. Selection depends on assembly process requirements and volume considerations.