SN74HC645DW Equivalent & Substitute Parts

Part Overview

The SN74HC645DW is a non-inverting transceiver logic IC manufactured by Texas Instruments, featuring 1 element with 8 bits per element and 3-state output capability in a 20-SOIC package. This component operates across a 2V to 6V supply voltage range with symmetric output current characteristics of 7.8mA for both high and low states.

The SN74HC645DW is classified as Last Time Buy, indicating discontinued production. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for systems utilizing this transceiver architecture.

Substiute Parts

SN74HC645DW

Texas InstrumentsIn Stock: 1163SN74HC645DW Datasheet

Current PartRFQ

SN74HC645DWR

Texas InstrumentsIn Stock: 3210SN74HC645DWR Datasheet

MFR RecommendedRFQ

SN74HC245DW

Texas InstrumentsIn Stock: 5943SN74HC245DW Datasheet

Parametric EquivalentRFQ

74HC245D,653

Nexperia USA Inc.In Stock: 228174HC245D,653 Datasheet

MFR RecommendedRFQ

MM74HC245AWM

onsemiIn Stock: 1911MM74HC245AWM Datasheet

Parametric EquivalentRFQ

SN74HC623DW

Texas InstrumentsIn Stock: 2270SN74HC623DW Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SN74HC645DW are qualified based on the following critical parameters that determine functional and mechanical compatibility:

Electrical Parameters:

• Logic Type: Transceiver, Non-Inverting
• Number of Elements: 1
• Number of Bits per Element: 8
• Output Type: 3-State
• Current - Output High, Low: 7.8mA, 7.8mA
• Voltage - Supply: 2V ~ 6V
• Operating Temperature Range: -40°C to 85°C minimum

Mechanical Parameters:

• Package / Case: 20-SOIC (0.295", 7.50mm Width)
• Mounting Type: Surface Mount

Compliance Parameters:

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

Parts meeting all electrical and mechanical parameters are classified as direct substitutes. Variations in product status, manufacturer, or base product number do not affect substitution eligibility when core parameters align.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: SN74HC645DWR

The SN74HC645DWR is the manufacturer-recommended substitute for the SN74HC645DW. Both parts are produced by Texas Instruments with identical electrical specifications, operating temperature range, and package configuration. The SN74HC645DWR maintains Active product status with higher inventory availability (3200 Pcs), ensuring supply chain continuity. Both parts are ROHS3 compliant with MSL 1 rating.

Secondary Recommendations:

SN74HC245DW (Texas Instruments) provides parametric equivalence with identical electrical and thermal characteristics. This part is discontinued at DiGi Electronics but remains available through alternative distribution channels. Use this option when SN74HC645DWR availability is constrained.

74HC245D,653 (Nexperia USA Inc.) qualifies as a direct substitute with all critical electrical parameters matching the original part. This part offers an extended operating temperature range (-40°C to 125°C), providing additional thermal margin. Active product status and ROHS3 compliance support long-term availability.

SN74HC623DW (Texas Instruments) meets all electrical and mechanical requirements with Active product status. This part maintains the same supply voltage range, output current characteristics, and package footprint as the original design.

Alternative Option: MM74HC245AWM (onsemi)

The MM74HC245AWM provides electrical and mechanical compatibility with one consideration: Moisture Sensitivity Level is rated at 3 (168 Hours) compared to MSL 1 for the primary part. This part is suitable for applications where moisture sensitivity handling procedures are implemented. Active product status ensures ongoing availability.

Frequently Asked Questions (FAQ)

Q: Can I use SN74HC645DWR as a direct replacement for SN74HC645DW?

A: Yes. The SN74HC645DWR is the manufacturer-recommended substitute with identical electrical specifications, operating temperature range (-40°C to 85°C), output current characteristics (7.8mA), supply voltage range (2V to 6V), and 20-SOIC package configuration. Both parts are ROHS3 compliant with MSL 1 rating.

Q: What is the difference between SN74HC645DW and SN74HC245DW?

A: Both parts share identical electrical parameters, thermal specifications, and package footprint. The primary difference is product status: SN74HC645DW is Last Time Buy while SN74HC245DW is discontinued at DiGi Electronics. Both are functionally equivalent for circuit design purposes.

Q: Why does 74HC245D,653 have a different operating temperature range?

A: The 74HC245D,653 manufactured by Nexperia USA Inc. is rated for -40°C to 125°C, compared to -40°C to 85°C for the original part. This extended range does not affect substitution eligibility. The part maintains all other critical electrical and mechanical parameters required for compatibility.

Q: Is MM74HC245AWM suitable for my application?

A: The MM74HC245AWM is electrically and mechanically compatible with the SN74HC645DW. The primary consideration is Moisture Sensitivity Level: this part is rated MSL 3 (168 Hours) versus MSL 1 (Unlimited) for the original. If your manufacturing process includes moisture sensitivity handling procedures, this part is suitable. Otherwise, select a part with MSL 1 rating.

Q: Are all substitute parts available in the same packaging format?

A: All listed substitute parts use the 20-SOIC (0.295", 7.50mm Width) surface mount package, ensuring mechanical compatibility with existing PCB designs. Packaging format (Tube, Cut Tape, or Digi-Reel) varies by supplier but does not affect electrical performance or board-level integration.

Q: Which substitute part offers the best supply chain availability?

A: The SN74HC645DWR offers the highest inventory availability at 3200 Pcs with Active product status. The 74HC245D,653 (Nexperia) provides 2200 Pcs with Active status as a secondary option. Both parts ensure long-term supply continuity.