SN74LS623DW Equivalent & Substitute Parts

Part Overview

The SN74LS623DW is a non-inverting transceiver logic IC manufactured by Texas Instruments, designed for 8-bit data bus applications with 3-state output capability. This component operates within a 4.75V to 5.25V supply voltage range and is housed in a 20-SOIC surface mount package. The part is classified as obsolete, making equivalent substitutes necessary for ongoing production and maintenance applications where this specific model is no longer readily available through standard distribution channels.

Substiute Parts

SN74LS623DW

Texas InstrumentsIn Stock: 2049SN74LS623DW Datasheet

Current PartRFQ

SN74LS245DW

onsemiIn Stock: 2044SN74LS245DW Datasheet

Parametric EquivalentRFQ

SN74LS645DW

Texas InstrumentsIn Stock: 1070SN74LS645DW Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SN74LS623DW are qualified based on the following critical parameters that must match or remain compatible:

• Logic Type: Transceiver, Non-Inverting
• Number of Elements: 1
• Number of Bits per Element: 8
• Output Type: 3-State
• Current - Output High, Low: 15mA, 24mA
• 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

The identified substitutes maintain electrical equivalence across these parameters, ensuring functional compatibility in existing circuit designs. Differences in manufacturer, product status, and compliance certifications are noted but do not affect core electrical performance within the specified operating conditions.

Parameter Comparison

Engineering Selection Recommendations

Both SN74LS245DW and SN74LS645DW provide electrical equivalence to the SN74LS623DW across all critical functional parameters. Selection between substitutes should consider the following factors:

SN74LS245DW (onsemi): Offers the highest inventory availability at 2030 units. However, this part carries RoHS non-compliant status, which may present constraints in applications subject to RoHS regulations or customer requirements.

SN74LS645DW (Texas Instruments): Maintains ROHS3 compliance and is supplied in Tube packaging. This part is designated as Last Time Buy, indicating limited future availability. Inventory of 1026 units is available. This option is preferred for applications requiring RoHS compliance and continued support from the original manufacturer.

For new designs or applications with strict compliance requirements, SN74LS645DW is the recommended substitute. For legacy system maintenance where RoHS compliance is not a constraint, SN74LS245DW provides equivalent electrical performance with superior inventory availability.

Frequently Asked Questions (FAQ)

Q: Can SN74LS245DW be used as a direct replacement for SN74LS623DW?

A: Yes. Both parts share identical electrical specifications including logic type, bit width, output configuration, current ratings, supply voltage range, operating temperature, and package form factor. The primary difference is RoHS compliance status.

Q: What is the significance of the "Last Time Buy" status on SN74LS645DW?

A: Last Time Buy designation indicates that the manufacturer will no longer produce this part after a specified date. Existing inventory represents the final available stock. For long-term production requirements, this status should be considered when planning component procurement.

Q: Are there any package compatibility concerns when substituting these parts?

A: No. All three parts use the identical 20-SOIC (0.295", 7.50mm Width) surface mount package. PCB footprints and assembly processes require no modification.

Q: Does RoHS compliance affect electrical performance?

A: No. RoHS compliance relates to material composition and environmental regulations, not electrical functionality. Both RoHS-compliant and non-compliant versions deliver identical electrical performance within specified operating parameters.

Q: Which substitute should be selected for high-volume production?

A: SN74LS245DW offers the highest inventory availability. However, if RoHS compliance is mandatory, SN74LS645DW must be selected despite lower inventory levels. Procurement planning should account for Last Time Buy status on SN74LS645DW.