74HCT27N,652 Equivalent & Substitute Parts

Part Overview

The 74HCT27N,652 is a NOR Gate IC with 3 channels and 3 inputs per channel, manufactured by NXP USA Inc. in a 14-DIP through-hole package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing system maintenance, repairs, and legacy design support. The 74HCT series logic gate remains functionally relevant despite its obsolete status, and direct substitutes are available from alternative manufacturers with compatible electrical and mechanical specifications.

Substiute Parts

74HCT27N,652

NXP USA Inc.In Stock: 119874HCT27N,652 Datasheet

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CD74HCT27E

Harris CorporationIn Stock: 2321CD74HCT27E Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74HCT27N,652 is determined by the following critical parameters:

• Logic Function: NOR Gate with identical 3-channel, 3-input configuration
• Electrical Specifications: Supply voltage range (4.5V ~ 5.5V), quiescent current (2 µA max), output current (4mA), and input logic levels must match or be compatible
• Propagation Delay: Maximum delay specification of 21ns @ 4.5V, 50pF establishes timing performance baseline
• Operating Temperature Range: Minimum -40°C operation required for compatibility
• Package Compatibility: 14-DIP through-hole package with 0.300" (7.62mm) pitch ensures mechanical and electrical pin compatibility
• Series Designation: 74HCT series logic gates maintain functional equivalence across manufacturers

The CD74HCT27E from Harris Corporation qualifies as a direct substitute based on matching logic type, circuit count, input configuration, supply voltage, output current, input logic levels, and package format.

Parameter Comparison

Engineering Selection Recommendations

The CD74HCT27E is functionally equivalent to the 74HCT27N,652 for direct substitution in through-hole applications. Both components share identical logic function, circuit configuration, and electrical operating parameters within the 4.5V to 5.5V supply range.

The CD74HCT27E exhibits a slightly extended propagation delay of 23ns compared to the 74HCT27N,652 at 21ns, both measured at 4.5V with 50pF load. This 2ns difference remains within typical system timing margins for standard logic applications and does not constitute a functional limitation.

The CD74HCT27E supports an extended operating temperature range of -55°C to 125°C, providing broader environmental coverage compared to the -40°C to 125°C range of the 74HCT27N,652.

Compliance considerations: The 74HCT27N,652 is RoHS3 compliant, while the CD74HCT27E is RoHS non-compliant. System-level compliance requirements must be evaluated when selecting between these alternatives.

Frequently Asked Questions (FAQ)

Q: Can the CD74HCT27E directly replace the 74HCT27N,652 in existing designs?

A: Yes. Both components are 14-DIP through-hole packages with identical pin configurations, logic function, and electrical specifications. Direct socket substitution is mechanically and electrically compatible.

Q: What is the significance of the 2ns propagation delay difference?

A: The CD74HCT27E propagation delay of 23ns versus 21ns for the 74HCT27N,652 represents a 9.5% increase. For standard logic applications, this difference is typically absorbed within system timing budgets and does not affect functional compatibility.

Q: Does the extended temperature range of the CD74HCT27E affect substitution suitability?

A: No. The CD74HCT27E operating range of -55°C to 125°C encompasses the 74HCT27N,652 range of -40°C to 125°C. Extended temperature capability provides additional environmental margin without introducing incompatibility.

Q: Are there RoHS compliance implications when substituting these parts?

A: Yes. The 74HCT27N,652 is RoHS3 compliant, while the CD74HCT27E is RoHS non-compliant. System-level regulatory requirements must be verified before substitution to ensure compliance with applicable standards.

Q: What packaging formats are available for these substitute parts?

A: Both the 74HCT27N,652 and CD74HCT27E are supplied in 14-DIP through-hole packages with 0.300" (7.62mm) pitch. The CD74HCT27E is available in tube packaging format.