74HCT640D,652 Equivalent & Substitute Parts

Part Overview

The 74HCT640D,652 is an inverting transceiver logic integrated circuit manufactured by NXP USA Inc. in a 20-SO surface mount package. This component functions as a 1-element, 8-bit inverting transceiver with 3-state output capability, designed for 5.5V logic applications. The part is classified as obsolete, making identification of functionally equivalent active alternatives necessary for ongoing design support and procurement.

Substiute Parts

74HCT640D,652

NXP USA Inc.In Stock: 95574HCT640D,652 Datasheet

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CD74HCT640M

Texas InstrumentsIn Stock: 3271CD74HCT640M Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74HCT640D,652 is determined by strict equivalence across the following critical parameters:

Functional Parameters:

• Logic type: Transceiver, Inverting
• Number of elements: 1
• Bits per element: 8
• Output configuration: 3-State

Electrical Parameters:

• Supply voltage range: 4.5V ~ 5.5V
• Output current capability: 6mA (high and low)
• Operating temperature range: Must encompass or exceed -40°C ~ 125°C

Physical Parameters:

• Package type: 20-SOIC surface mount
• Package dimensions: 0.295" width (7.50mm)

Compliance Parameters:

• RoHS3 compliance required
• MSL rating: 1 (Unlimited)

The CD74HCT640M from Texas Instruments meets all functional, electrical, and physical requirements for direct substitution. The extended operating temperature range (-55°C ~ 125°C) of the substitute part provides additional margin beyond the original specification.

Parameter Comparison

Engineering Selection Recommendations

The CD74HCT640M from Texas Instruments is a direct functional and electrical equivalent to the obsolete 74HCT640D,652. Both parts share identical logic architecture, pin configuration, electrical characteristics, and package specifications. The substitute part maintains full ROHS3 compliance and MSL rating equivalence.

The primary advantage of selecting the CD74HCT640M is product status: the part is currently active in production with established supply chains, whereas the original NXP part is obsolete. The extended operating temperature range of the Texas Instruments part (-55°C minimum versus -40°C minimum) provides additional thermal margin without introducing any compatibility concerns.

Both parts are certified under identical regulatory frameworks (ROHS3, REACH Unaffected, EAR99 ECCN classification), ensuring compliance continuity in applications requiring these certifications.

Frequently Asked Questions (FAQ)

Q: Can the CD74HCT640M be used as a direct replacement for the 74HCT640D,652?

A: Yes. Both parts are 74HCT series inverting transceivers with identical functional specifications, electrical ratings, and 20-SOIC package dimensions. No circuit modifications are required.

Q: Are there any differences in pin configuration between these parts?

A: No. Both parts use the same 20-pin SOIC package with identical pin assignments and signal definitions.

Q: Does the extended temperature range of the CD74HCT640M affect compatibility?

A: No. The extended operating range (-55°C to 125°C versus -40°C to 125°C) represents an expansion of the original specification and does not introduce any compatibility issues. Applications operating within the original temperature range remain fully compatible.

Q: Are both parts RoHS compliant?

A: Yes. Both the 74HCT640D,652 and CD74HCT640M are ROHS3 compliant with MSL rating 1 (Unlimited).

Q: What is the primary reason for substitution?

A: The 74HCT640D,652 is classified as obsolete. The CD74HCT640M provides an active, currently manufactured alternative with identical electrical and functional characteristics.

Q: Are there any supply chain considerations?

A: The CD74HCT640M is actively produced by Texas Instruments with established distribution channels. The original NXP part is no longer in production, making the substitute the recommended choice for new designs and ongoing procurement.