SN74LS640-1DW Equivalent & Substitute Parts

Part Overview

The SN74LS640-1DW is a Logic Transceiver, Inverting integrated circuit manufactured by Texas Instruments. This device functions as a 1 Element, 8 Bit per Element transceiver with 3-State output capability, housed in a 20-SOIC surface mount package. The part operates within a supply voltage range of 4.75V to 5.25V and is rated for operating temperatures from 0°C to 70°C.

The SN74LS640-1DW 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

SN74LS640-1DW

Texas InstrumentsIn Stock: 1492SN74LS640-1DW Datasheet

Current PartRFQ

SN74LS640DWR

Texas InstrumentsIn Stock: 3497SN74LS640DWR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SN74LS640-1DW is determined by strict equivalence across the following critical parameters:

• Logic Type: Transceiver, Inverting
• Number of Elements: 1
• Number of Bits per Element: 8
• Output Type: 3-State
• Voltage - Supply: 4.75V ~ 5.25V
• Operating Temperature: 0°C ~ 70°C (TA)
• Package / Case: 20-SOIC (0.295", 7.50mm Width)
• Mounting Type: Surface Mount
• Series: 74LS

The SN74LS640DWR qualifies as a direct substitute based on identical functional specifications, electrical characteristics, and physical packaging. The primary distinction between these parts is packaging format: the main part is supplied in Tube packaging, while the substitute is supplied in Tape & Reel (TR) format. Both parts maintain the same base product number (74LS640) and are manufactured by Texas Instruments.

Parameter Comparison

Engineering Selection Recommendations

The SN74LS640DWR is the direct substitute for the SN74LS640-1DW. Both parts are manufactured by Texas Instruments, maintain identical functional and electrical specifications, and are housed in the same 20-SOIC package. The SN74LS640DWR carries Active product status, ensuring continued availability and manufacturing support.

The primary consideration for component selection is packaging format. The SN74LS640-1DW is supplied in Tube packaging, suitable for lower-volume applications and manual assembly processes. The SN74LS640DWR is supplied in Tape & Reel (TR) format, optimized for automated pick-and-place assembly and higher-volume production environments.

Both parts are ROHS3 Compliant and carry MSL Level 1 (Unlimited) moisture sensitivity rating, indicating equivalent environmental handling and storage requirements. Selection between these parts should be based on production volume, assembly methodology, and supply chain requirements rather than functional or electrical considerations.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS640DWR be used as a direct replacement for the SN74LS640-1DW?

A: Yes. The SN74LS640DWR is functionally and electrically equivalent to the SN74LS640-1DW. Both parts share identical logic type, element configuration, bit width, output type, supply voltage range, operating temperature range, and physical package dimensions. The parts are interchangeable from a circuit design and performance perspective.

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

A: Tube packaging supplies individual components in a plastic tube, typically used for lower-volume orders and manual assembly. Tape & Reel (TR) packaging supplies components on a continuous carrier tape wound on a reel, optimized for automated assembly equipment. Both packaging formats contain the same component; the difference is in delivery and handling method.

Q: Are there any electrical performance differences between these parts?

A: The output low current specification differs slightly: the SN74LS640-1DW is rated at 48mA, while the SN74LS640DWR is rated at 24mA. All other electrical parameters, including supply voltage, operating temperature range, and output high current, are identical. Circuit designs must accommodate the lower output low current specification of the SN74LS640DWR.

Q: What does Last Time Buy product status mean?

A: Last Time Buy indicates that Texas Instruments has discontinued active production of the SN74LS640-1DW. Existing inventory may be available from distributors, but no new manufacturing runs are planned. The SN74LS640DWR, with Active product status, represents the recommended path for ongoing procurement and new designs.

Q: Are both parts RoHS compliant?

A: Yes. Both the SN74LS640-1DW and SN74LS640DWR are ROHS3 Compliant and carry MSL Level 1 (Unlimited) moisture sensitivity rating, indicating equivalent environmental compliance and handling requirements.