SN74LS642NS Equivalent & Substitute Parts

Part Overview

The SN74LS642NS is a logic transceiver integrated circuit manufactured by Texas Instruments, classified as an inverting transceiver with 1 element and 8 bits per element. The device features open collector output configuration and is housed in a 20-SOIC surface mount package. This component is designated as Last Time Buy status, indicating discontinued production. Identifying equivalent substitute parts is necessary to ensure continued design support, maintain supply chain continuity, and facilitate component procurement for new production runs or design revisions.

Substiute Parts

SN74LS642NS

Texas InstrumentsIn Stock: 2123SN74LS642NS Datasheet

Current PartRFQ

SN74LS642NSR

Texas InstrumentsIn Stock: 2459SN74LS642NSR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SN74LS642NS is determined by strict equivalence across the following critical parameters:

Functional Parameters:

• Logic Type: Transceiver, Inverting
• Number of Elements: 1
• Number of Bits per Element: 8
• Output Type: Open Collector

Electrical Parameters:

• Voltage - Supply: 4.75V ~ 5.25V
• Operating Temperature: 0°C ~ 70°C (TA)
• Current - Output Low: 24mA (minimum requirement)

Physical Parameters:

• Package / Case: 20-SOIC (0.209", 5.30mm Width)
• Mounting Type: Surface Mount

Compliance Parameters:

• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level (MSL): 1 (Unlimited)

The SN74LS642NSR qualifies as a direct substitute based on identical functional, electrical, and physical specifications. The primary distinction is packaging format (Tape & Reel versus tube) and product status (Active versus Last Time Buy).

Parameter Comparison

Engineering Selection Recommendations

The SN74LS642NSR is the direct substitute for the SN74LS642NS. Both components are manufactured by Texas Instruments and maintain identical electrical and functional specifications across all critical parameters. The SN74LS642NSR carries Active product status, ensuring long-term availability and continued manufacturing support, whereas the SN74LS642NS is designated Last Time Buy.

Both parts satisfy ROHS3 compliance requirements and maintain MSL Level 1 (Unlimited) moisture sensitivity classification, suitable for standard storage and handling conditions. The packaging format difference (Tape & Reel versus tube) does not affect electrical or mechanical compatibility; selection between these formats depends on production volume requirements and assembly line equipment specifications.

For new designs or production transitions, the SN74LS642NSR is the recommended selection due to its Active status and assured supply continuity.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS642NSR be used as a direct replacement for the SN74LS642NS in existing designs?

A: Yes. The SN74LS642NSR is electrically and functionally identical to the SN74LS642NS. Both components share the same logic type (Transceiver, Inverting), element configuration (1 element, 8 bits per element), output type (Open Collector), supply voltage range (4.75V ~ 5.25V), operating temperature range (0°C ~ 70°C), and package specification (20-SOIC). No circuit modifications are required.

Q: What is the difference between the SN74LS642NS and SN74LS642NSR?

A: The primary differences are product status and packaging format. The SN74LS642NS is Last Time Buy status with tube packaging, while the SN74LS642NSR is Active status with Tape & Reel packaging. Electrical and functional specifications are identical.

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

A: No. Both the SN74LS642NS and SN74LS642NSR are ROHS3 compliant and carry MSL Level 1 (Unlimited) classification. Compliance certifications are equivalent.

Q: Which packaging format should be selected for production?

A: Packaging format selection depends on production volume and assembly equipment. Tape & Reel (SN74LS642NSR) is standard for high-volume automated assembly. Tube packaging (SN74LS642NS) is typically used for lower volumes or manual assembly. Both formats contain identical components.

Q: Is the SN74LS642NSR suitable for new product designs?

A: Yes. The SN74LS642NSR is the appropriate choice for new designs due to its Active product status, which ensures continued manufacturing support and supply availability.