74HCT540N Equivalent & Substitute Parts

Part Overview

The 74HCT540N is a logic buffer integrated circuit manufactured by NXP USA Inc., designed as an inverting buffer with 1 element, 8 bits per element, and 3-state output capability. This component operates within a 4.5V to 5.5V supply voltage range and is housed in a 20-DIP package. The part is classified as obsolete, making equivalent and substitute parts necessary for ongoing system maintenance and new design implementations where this logic function is required.

Substiute Parts

74HCT540N,652

NXP USA Inc.In Stock: 81274HCT540N,652 Datasheet

Current PartRFQ

CD74HCT540E

Harris CorporationIn Stock: 1747CD74HCT540E Datasheet

DirectRFQ

SN74HCT540N

Texas InstrumentsIn Stock: 2133SN74HCT540N Datasheet

DirectRFQ

TC74HCT540AP(F)

Toshiba Semiconductor and StorageIn Stock: 1059TC74HCT540AP(F) Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74HCT540N is determined by strict equivalence across the following critical parameters:

• Logic Type: Buffer, Inverting
• Number of Elements: 1
• Number of Bits per Element: 8
• Output Type: 3-State
• Current - Output High, Low: 6mA, 6mA
• Voltage - Supply: 4.5V ~ 5.5V
• Mounting Type: Through Hole
• Package / Case: 20-DIP (0.300", 7.62mm)
• Base Product Number: 74HCT540

All substitute parts listed maintain these core electrical and mechanical specifications, ensuring functional compatibility within systems designed for the 74HCT540N. Variations in operating temperature range, product status, and compliance certifications are noted but do not affect the core substitution relationship.

Parameter Comparison

Engineering Selection Recommendations

For applications requiring the 74HCT540N logic buffer function, the following selection criteria apply based on product status and compliance:

Active Product Status with Full Compliance: The SN74HCT540N (Texas Instruments) and TC74HCT540AP(F) (Toshiba Semiconductor and Storage) are both active products with current manufacturing support. Both maintain ROHS3 or RoHS compliance, making them suitable for new designs and systems requiring regulatory compliance. The SN74HCT540N operates within -40°C to 85°C, while the TC74HCT540AP(F) operates within the same temperature range.

Obsolete Product Status: The CD74HCT540E (Harris Corporation) is obsolete and non-compliant with RoHS standards. This part is functionally equivalent but should be selected only when legacy system maintenance requires exact historical component matching and RoHS compliance is not a requirement.

The original 74HCT540N (NXP USA Inc.) is obsolete but ROHS3 compliant. Substitute parts with active status are preferred for new implementations.

Frequently Asked Questions (FAQ)

Q: Can the SN74HCT540N replace the 74HCT540N in existing designs? A: Yes. The SN74HCT540N maintains all critical electrical parameters: 1 element, 8 bits per element, 3-state output, 6mA output current, 4.5V to 5.5V supply voltage, and 20-DIP package. The operating temperature range differs (-40°C to 85°C versus -40°C to 125°C), which must be evaluated against system requirements.

Q: What is the difference between the CD74HCT540E and other substitutes? A: The CD74HCT540E is functionally equivalent but is obsolete and RoHS non-compliant. It offers an extended operating temperature range (-55°C to 125°C) compared to the original part. Selection should be based on compliance requirements and temperature specifications of the target application.

Q: Are all substitute parts pin-compatible with the 74HCT540N? A: Yes. All substitute parts use the 20-DIP (0.300", 7.62mm) package with identical pinout, ensuring direct mechanical and electrical compatibility without PCB modifications.

Q: Which substitute is recommended for new designs? A: The SN74HCT540N (Texas Instruments) and TC74HCT540AP(F) (Toshiba) are both active products with current manufacturing support and RoHS compliance. Selection between these two should be based on supplier availability, lead time, and cost considerations.

Q: Does operating temperature range affect substitution compatibility? A: Operating temperature range does not affect functional substitution but must be evaluated against system thermal requirements. The CD74HCT540E supports -55°C to 125°C, while the SN74HCT540N and TC74HCT540AP(F) support -40°C to 85°C. The original 74HCT540N supports -40°C to 125°C. Select based on the application's minimum and maximum operating temperatures.