SN74HC540DBR Equivalent & Substitute Parts

Part Overview

The SN74HC540DBR is an inverting buffer logic integrated circuit manufactured by Texas Instruments, designed for 6V operation with 3-state output capability. This device belongs to the 74HC logic family and is classified as obsolete. Due to its obsolete status and limited availability from the original manufacturer, identifying equivalent and substitute parts is essential for design continuity and procurement flexibility. Substitute parts must maintain identical electrical characteristics and compatible packaging to ensure functional equivalence in circuit applications.

Substiute Parts

SN74HC540DBR

Texas InstrumentsIn Stock: 818SN74HC540DBR Datasheet

Current PartRFQ

74HC540DB,112

Nexperia USA Inc.In Stock: 123074HC540DB,112 Datasheet

UpgradeRFQ

MM74HC540MTC

Fairchild SemiconductorIn Stock: 2600MM74HC540MTC Datasheet

MFR RecommendedRFQ

MM74HC540MTCX

onsemiIn Stock: 8227MM74HC540MTCX Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SN74HC540DBR are qualified based on the following critical parameters that determine functional equivalence:

Electrical Equivalence Criteria:

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

Mechanical Compatibility Criteria:

• Mounting Type: Surface Mount
• Package / Case: 20-SSOP or 20-TSSOP (both 20-pin small outline packages with compatible pinouts)

Compliance Criteria:

• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level: 1 (Unlimited)

Substitute parts are grouped into two categories: direct package equivalents (20-SSOP) and compatible package variants (20-TSSOP) that maintain identical electrical performance and pinout compatibility.

Parameter Comparison

Engineering Selection Recommendations

Direct Package Equivalent (20-SSOP): The 74HC540DB,112 from Nexperia USA Inc. is a direct substitute for the SN74HC540DBR. Both devices use the 20-SSOP package with identical pinout and electrical specifications. The Nexperia part offers an extended operating temperature range (-40°C ~ 125°C) compared to the original part, providing additional thermal margin. Both parts maintain ROHS3 compliance and MSL 1 rating. This substitute is recommended for applications requiring exact package compatibility.

Compatible Package Variants (20-TSSOP): The MM74HC540MTC (Fairchild Semiconductor) and MM74HC540MTCX (onsemi) are functionally equivalent substitutes using the 20-TSSOP package. Both devices maintain identical electrical performance and pinout compatibility with the original part. The MM74HC540MTCX from onsemi is classified as active product status with ROHS3 compliance and MSL 1 rating, ensuring long-term availability. The MM74HC540MTC from Fairchild is also active but lacks specified compliance documentation. These substitutes are suitable for applications where the narrower 20-TSSOP package (0.173" width versus 0.209" for SSOP) is acceptable for PCB layout requirements.

Frequently Asked Questions (FAQ)

Q: Can the 74HC540DB,112 be used as a direct replacement for the SN74HC540DBR? A: Yes. Both parts use the 20-SSOP package with identical pinout, electrical specifications, and output drive capability. The Nexperia part is a direct substitute with extended temperature range capability.

Q: What is the difference between the 20-SSOP and 20-TSSOP packages? A: Both are 20-pin small outline packages with identical pinouts and electrical compatibility. The primary difference is physical width: 20-SSOP measures 0.209" (5.30mm) while 20-TSSOP measures 0.173" (4.40mm). The narrower TSSOP package may require PCB layout verification to ensure component clearance and trace routing compatibility.

Q: Are the onsemi and Fairchild substitutes suitable for high-temperature applications? A: Both the MM74HC540MTC and MM74HC540MTCX are rated for -40°C ~ 85°C operating temperature, identical to the original SN74HC540DBR. For applications requiring extended temperature operation, the Nexperia 74HC540DB,112 offers -40°C ~ 125°C capability.

Q: Do all substitute parts meet RoHS compliance requirements? A: The 74HC540DB,112 from Nexperia and MM74HC540MTCX from onsemi are confirmed ROHS3 compliant. The MM74HC540MTC from Fairchild does not have specified compliance documentation in the provided data.

Q: What is the moisture sensitivity level for these parts? A: The SN74HC540DBR, 74HC540DB,112, and MM74HC540MTCX all carry MSL 1 (Unlimited) rating, indicating no moisture sensitivity restrictions. The MM74HC540MTC does not have specified MSL documentation.

Q: Which substitute offers the best long-term availability? A: The MM74HC540MTCX from onsemi is classified as active product status with confirmed inventory of 8201 pieces, providing the strongest availability assurance. The MM74HC540MTC from Fairchild is also active status. Both Nexperia and Texas Instruments parts are classified as obsolete.