74HC640D,653 Equivalent & Substitute Parts

Part Overview

The 74HC640D,653 is a logic transceiver IC manufactured by NXP USA Inc., designed as an inverting transceiver with 1 element, 8 bits per element, and 3-state output capability. This component operates across a 2V to 6V supply voltage range and is housed in a 20-SO surface mount package. The part is currently listed as obsolete, making identification of functionally equivalent alternatives necessary for ongoing system support and component procurement.

Substiute Parts

74HC640D,653

NXP USA Inc.In Stock: 76574HC640D,653 Datasheet

Current PartRFQ

CD74HC640M

Harris CorporationIn Stock: 1976CD74HC640M Datasheet

UpgradeRFQ

SN74HC640DW

Texas InstrumentsIn Stock: 896SN74HC640DW Datasheet

MFR RecommendedRFQ

SN74HC640DWR

Texas InstrumentsIn Stock: 2674SN74HC640DWR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 74HC640D,653 are qualified based on the following critical parameters that determine functional equivalence:

Core Electrical Parameters:

• Logic Type: Transceiver, 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

Physical Parameters:

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

Compliance Parameters:

• RoHS Status
• REACH Status
• ECCN Classification

All identified substitute parts maintain identical electrical specifications and package dimensions, ensuring direct functional replacement capability in circuit applications.

Parameter Comparison

Engineering Selection Recommendations

SN74HC640DWR (Texas Instruments) - Primary Selection

The SN74HC640DWR is the preferred substitute for the 74HC640D,653. This part maintains full electrical and physical compatibility while offering the advantage of active product status. It carries ROHS3 compliance certification and REACH unaffected status, meeting current regulatory requirements. The tape and reel packaging format supports high-volume procurement workflows.

SN74HC640DW (Texas Instruments) - Secondary Selection

The SN74HC640DW provides equivalent functionality with ROHS3 compliance and REACH unaffected status. However, this variant is discontinued at DiGi Electronics, limiting long-term availability. The operating temperature range (-40°C to 85°C) is narrower than the original part, which may impact applications requiring extended temperature operation.

CD74HC640M (Harris Corporation) - Limited Compatibility

The CD74HC640M maintains electrical equivalence and offers an extended operating temperature range (-55°C to 125°C). However, this part carries RoHS non-compliant status, which may conflict with procurement policies or regulatory requirements in certain applications or regions.

Frequently Asked Questions (FAQ)

Q: Can the SN74HC640DWR directly replace the 74HC640D,653 in existing designs?

A: Yes. The SN74HC640DWR maintains identical electrical specifications (logic type, bit configuration, output type, current ratings, and supply voltage) and is housed in the same 20-SOIC package. Direct pin-for-pin substitution is supported.

Q: What is the difference between SN74HC640DW and SN74HC640DWR?

A: Both parts are electrically identical. The primary difference is packaging format: SN74HC640DW is supplied in tube packaging, while SN74HC640DWR is supplied in tape and reel format. The tape and reel variant is typically preferred for automated assembly and high-volume applications.

Q: Why is the CD74HC640M listed as RoHS non-compliant?

A: The CD74HC640M was manufactured prior to RoHS3 compliance requirements. While electrically equivalent, its non-compliant status may restrict use in applications subject to RoHS regulations or procurement policies requiring certified compliance.

Q: Does the narrower operating temperature range of the SN74HC640DW affect compatibility?

A: The SN74HC640DW operates from -40°C to 85°C, compared to the original part's -40°C to 125°C range. Compatibility depends on the application's actual operating temperature requirements. Applications requiring operation above 85°C would require the CD74HC640M or original specification verification.

Q: Are all substitute parts available in the same package?

A: Yes. All substitute parts are housed in the 20-SOIC (0.295", 7.50mm Width) surface mount package, ensuring mechanical compatibility with existing PCB layouts and assembly processes.