74HC640DB,112 Equivalent & Substitute Parts

Part Overview

The 74HC640DB,112 is an inverting transceiver logic integrated circuit manufactured by NXP USA Inc., designed for 8-bit data inversion with 3-state output capability. This component operates across a 2V to 6V supply voltage range and is housed in a 20-SSOP package. The part is classified as Obsolete, making equivalent substitutes necessary for new designs and ongoing production requirements. Substitute parts maintain functional equivalence while offering improved availability and product status.

Substiute Parts

74HC640DB,112

NXP USA Inc.In Stock: 113174HC640DB,112 Datasheet

Current PartRFQ

SN74HC640PW

Texas InstrumentsIn Stock: 1615SN74HC640PW Datasheet

MFR RecommendedRFQ

SN74HC640PWR

Texas InstrumentsIn Stock: 8863SN74HC640PWR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 74HC640DB,112 are qualified based on the following electrical and mechanical parameters:

Electrical Equivalence Criteria:

• Logic Type: Transceiver, Inverting (identical function)
• Number of Elements: 1
• Number of Bits per Element: 8
• Output Type: 3-State
• Current - Output High, Low: 7.8mA, 7.8mA (identical drive capability)
• Voltage - Supply: 2V ~ 6V (identical operating range)
• Series: 74HC (same logic family)

Mechanical Compatibility Considerations:

• Package type differences (SSOP vs. TSSOP) require PCB layout verification
• Pin count remains constant at 20 pins
• Physical dimensions vary between package styles

The substitute parts SN74HC640PW and SN74HC640PWR are manufactured by Texas Instruments and maintain full electrical equivalence to the original part while offering improved product status and availability.

Parameter Comparison

Engineering Selection Recommendations

SN74HC640PWR (Texas Instruments) - Recommended Primary Substitute

The SN74HC640PWR is the preferred substitute for new designs and production. This part maintains full electrical equivalence with identical output current specifications and supply voltage range. The Active product status ensures long-term availability and supply chain stability. The Tape & Reel packaging format supports automated assembly processes. The 20-TSSOP package offers a smaller physical footprint (0.173" width) compared to the original 20-SSOP package, enabling more compact PCB layouts.

SN74HC640PW (Texas Instruments) - Secondary Substitute

The SN74HC640PW provides equivalent electrical performance and is available in Tube packaging. Last Time Buy status indicates limited future availability. This part is suitable for applications where tube packaging meets procurement requirements or where existing inventory must be consumed before transitioning to the PWR variant.

Temperature Range Consideration

Both Texas Instruments substitutes operate within -40°C to 85°C, which is narrower than the original part's -40°C to 125°C range. Applications requiring operation above 85°C require design review and alternative component selection.

Frequently Asked Questions (FAQ)

Q: Are the SN74HC640PW and SN74HC640PWR electrically identical to the 74HC640DB,112?

A: Yes. Both Texas Instruments parts maintain identical output current specifications (7.8mA high and low), supply voltage range (2V ~ 6V), and logic function (inverting transceiver with 8-bit, 3-state output). The 74HC series designation confirms compatibility within the same logic family.

Q: What is the difference between the 20-SSOP and 20-TSSOP packages?

A: The 20-SSOP package (original) measures 0.209" in width, while the 20-TSSOP package (substitutes) measures 0.173" in width. Both are surface-mount packages with 20 pins. PCB footprint and solder reflow profiles differ between these package types. Design verification is required when substituting between these packages.

Q: Can I use SN74HC640PWR in place of 74HC640DB,112 without PCB modifications?

A: Electrical substitution is direct. However, the different package type (TSSOP vs. SSOP) requires PCB footprint changes. Pin assignments remain identical, but physical placement and solder pad geometry differ. PCB layout redesign is necessary.

Q: Why is the operating temperature range different for the substitute parts?

A: The Texas Instruments SN74HC640 variants specify -40°C to 85°C operating range, while the NXP original extends to 125°C. Applications requiring the full 125°C range must retain the original part or identify alternative components with equivalent extended temperature specifications.

Q: Which substitute should I select for new production?

A: SN74HC640PWR is recommended for new designs. Active product status ensures availability, Tape & Reel packaging supports automated assembly, and the smaller TSSOP footprint enables compact designs. Verify PCB layout compatibility with the 20-TSSOP package before implementation.

Q: Are both substitutes RoHS3 compliant?

A: Yes. The 74HC640DB,112, SN74HC640PW, and SN74HC640PWR are all ROHS3 Compliant, meeting environmental and regulatory requirements for lead-free manufacturing.