74HCT27D,652 NOR Gate IC Equivalent & Substitute Parts

Part Overview

The 74HCT27D,652 is a 3-channel NOR gate logic IC manufactured by Nexperia USA Inc. in a 14-SOIC surface mount package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The part operates within a 4.5V to 5.5V supply voltage range and is suitable for TTL-compatible logic applications requiring NOR gate functionality.

Substiute Parts

74HCT27D,652

Nexperia USA Inc.In Stock: 74974HCT27D,652 Datasheet

Current PartRFQ

CD74HC27M

Harris CorporationIn Stock: 22293CD74HC27M Datasheet

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CD74HCT27M

Texas InstrumentsIn Stock: 4524CD74HCT27M Datasheet

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CD74HCT27M96

Texas InstrumentsIn Stock: 2185CD74HCT27M96 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the 74HCT27D,652 is determined by the following critical parameters:

• Logic Configuration: All substitutes must provide 3-channel NOR gate functionality with 3 inputs per channel
• Package Compatibility: All substitutes must use 14-SOIC surface mount packaging with identical physical dimensions (0.154", 3.90mm width)
• Supply Voltage Range: Substitutes operating at 4.5V ~ 5.5V (TTL-compatible) are direct replacements; parts with extended voltage ranges (2V ~ 6V) are compatible but operate outside the original specification
• Output Drive Capability: Current output specifications must meet or exceed 4mA for both high and low states
• Propagation Delay: Maximum propagation delay at specified conditions determines timing compatibility
• Operating Temperature Range: Minimum operating temperature of -40°C or lower is required for full compatibility

Three substitute parts meet these criteria with varying degrees of specification alignment and product status.

Parameter Comparison

Engineering Selection Recommendations

CD74HCT27M (Texas Instruments) provides the closest electrical and compliance match to the 74HCT27D,652. Both parts operate at 4.5V ~ 5.5V supply voltage, share identical input logic levels, and maintain ROHS3 compliance. The propagation delay difference of 2ns (23ns vs. 21ns) is within acceptable tolerance for most applications. However, this part is discontinued at DiGi Electronics, limiting availability.

CD74HCT27M96 (Texas Instruments) is the recommended primary substitute. It maintains identical electrical specifications to the 74HCT27D,652 within the 4.5V ~ 5.5V operating range, including input logic levels, output drive current, and propagation delay characteristics. This part carries Active product status, ensuring ongoing availability. ROHS3 compliance and MSL 1 rating match the original specification. The Tape & Reel packaging format is suitable for production environments.

CD74HC27M (Harris Corporation) operates at an extended voltage range of 2V ~ 6V, making it compatible but outside the original 4.5V ~ 5.5V specification window. The faster propagation delay (16ns @ 6V) and higher output drive current (5.2mA) provide performance margin. However, RoHS non-compliance and obsolete status limit its suitability for new designs. This part is appropriate only when legacy system requirements mandate the 74HC series.

Frequently Asked Questions (FAQ)

Q: Can CD74HC27M be used as a direct replacement for 74HCT27D,652?

A: CD74HC27M is functionally compatible but operates outside the original specification. The 74HC series supports 2V ~ 6V supply voltage, while the original part requires 4.5V ~ 5.5V. Input logic levels differ (0.5V ~ 1.8V for low, 1.5V ~ 4.2V for high versus 0.8V and 2V respectively). Use only if system design accommodates these differences. RoHS non-compliance may also restrict use in regulated applications.

Q: What is the difference between CD74HCT27M and CD74HCT27M96?

A: Both parts are manufactured by Texas Instruments and share identical electrical specifications. The primary difference is packaging format: CD74HCT27M is supplied in Tube packaging, while CD74HCT27M96 uses Tape & Reel format. CD74HCT27M96 has Active product status, ensuring continued availability, whereas CD74HCT27M is discontinued at DiGi Electronics.

Q: Are all substitute parts pin-compatible with the original 74HCT27D,652?

A: Yes. All substitute parts use the 14-SOIC package with identical physical dimensions (0.154", 3.90mm width) and maintain the same pin configuration for 3-channel NOR gate functionality.

Q: Does propagation delay variation affect circuit performance?

A: The maximum propagation delay difference is 2ns (21ns for the original versus 23ns for CD74HCT27M and CD74HCT27M96). This variation is negligible in most logic applications. CD74HC27M exhibits faster propagation (16ns @ 6V), but this measurement is taken at 6V rather than 4.5V, making direct comparison inappropriate.

Q: Which substitute part should be selected for new production designs?

A: CD74HCT27M96 is the recommended choice for new designs. It maintains Active product status, ensuring long-term availability, and provides full compliance with ROHS3 requirements and MSL 1 moisture sensitivity specifications. Electrical parameters match the original specification within the 4.5V ~ 5.5V operating range.