74VHC27M NOR Gate IC Equivalent & Substitute Parts

Part Overview

The 74VHC27M is a 3-channel NOR gate logic IC manufactured by onsemi, housed in a 14-SOIC surface mount package. This component implements three independent 3-input NOR logic functions and operates across a 2V to 5.5V supply voltage range. The product is currently classified as obsolete, making identification of functionally equivalent alternatives essential for design continuity and procurement planning.

Substiute Parts

74VHC27M

onsemiIn Stock: 82874VHC27M Datasheet

Current PartRFQ

SN74LV27AD

Texas InstrumentsIn Stock: 1717SN74LV27AD Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74VHC27M is determined by the following critical parameters:

• Logic Function: NOR gate with 3 channels and 3 inputs per channel
• Package Type: 14-SOIC surface mount form factor
• Supply Voltage Range: 2V to 5.5V compatibility
• Operating Temperature Range: -40°C to 85°C
• Input/Output Logic Levels: 0.5V (low) and 1.5V (high) thresholds
• Propagation Delay: Maximum 7.9ns at 5V with 50pF load

The SN74LV27AD from Texas Instruments meets all functional and electrical requirements for direct substitution. Both parts share identical logic architecture, package specifications, and core electrical characteristics within acceptable engineering tolerances.

Parameter Comparison

Engineering Selection Recommendations

The SN74LV27AD is a qualified substitute for the 74VHC27M based on functional equivalence and electrical compatibility. Key considerations:

• Electrical Performance: Both parts deliver identical propagation delay (7.9ns) and logic thresholds, ensuring timing-critical applications maintain specification compliance.
• Package Compatibility: Identical 14-SOIC footprint enables direct PCB layout reuse without redesign.
• Supply Voltage: Both operate across the full 2V to 5.5V range, supporting mixed-voltage system designs.
• Quiescent Current Difference: The SN74LV27AD exhibits 20 µA maximum quiescent current versus 2 µA for the 74VHC27M. This 10x difference is acceptable for most applications but should be evaluated in power-sensitive designs.
• Output Drive Current: The SN74LV27AD provides 12mA output drive (versus 8mA), offering improved fanout capability.
• Product Status: The SN74LV27AD carries Last Time Buy status, providing a defined procurement window for obsolescence planning.
• Compliance: The SN74LV27AD is RoHS3 compliant, supporting modern supply chain and environmental requirements.

Frequently Asked Questions (FAQ)

Q: Can the SN74LV27AD replace the 74VHC27M in existing designs?

A: Yes. Both parts implement identical 3-channel, 3-input NOR gate logic in the same 14-SOIC package with matching supply voltage ranges and logic thresholds. Direct substitution is electrically valid.

Q: What is the difference in quiescent current between these parts?

A: The 74VHC27M draws 2 µA maximum quiescent current, while the SN74LV27AD draws 20 µA. For battery-powered or ultra-low-power applications, this difference may require power budget reassessment.

Q: Are the output drive currents compatible?

A: The SN74LV27AD provides 12mA output drive compared to 8mA for the 74VHC27M. This higher drive capability is backward compatible and improves fanout margin in most circuit topologies.

Q: Do both parts share the same PCB footprint?

A: Yes. Both use the 14-SOIC (0.154", 3.90mm width) surface mount package, enabling direct PCB layout reuse without modification.

Q: What is the procurement status of these parts?

A: The 74VHC27M is obsolete. The SN74LV27AD is Last Time Buy status, indicating a defined window for procurement before discontinuation.

Q: Are there compliance or certification differences?

A: The SN74LV27AD is RoHS3 compliant. Both parts are REACH unaffected and carry EAR99 export classification.