74F139SCX Equivalent & Substitute Parts

Part Overview

The 74F139SCX is a Decoder/Demultiplexer IC with 1 x 2:4 circuit configuration in a 16-SOIC surface mount package, manufactured by onsemi. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. The 74F139 series provides logic-level decoding and demultiplexing functionality suitable for digital signal routing and selection applications.

Substiute Parts

74F139SCX

onsemiIn Stock: 5044374F139SCX Datasheet

Current PartRFQ

MC74AC139DR2G

onsemiIn Stock: 3782MC74AC139DR2G Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74F139SCX is determined by the following critical parameters:

• Circuit Configuration: Must maintain 1 x 2:4 decoder/demultiplexer topology with 2 independent circuits
• Package Type: Must be 16-SOIC surface mount package with identical pinout
• Functional Equivalence: Decoder/demultiplexer logic function must be preserved
• Supply Voltage Compatibility: Operating voltage range must accommodate system requirements
• Output Current Capability: Output drive current must meet or exceed application demands
• Operating Temperature Range: Must support the intended thermal environment

The MC74AC139DR2G qualifies as a direct substitute based on matching circuit configuration, package type, and functional equivalence, while offering enhanced electrical performance characteristics and active product status.

Parameter Comparison

Engineering Selection Recommendations

The MC74AC139DR2G is the qualified substitute for the obsolete 74F139SCX. Selection is based on:

• Functional Compatibility: Identical 1 x 2:4 decoder/demultiplexer circuit configuration and pinout in matching 16-SOIC package
• Product Status: MC74AC139DR2G maintains active production status, ensuring long-term availability and supply chain continuity
• Compliance: Both parts maintain REACH Unaffected status and equivalent moisture sensitivity ratings
• Electrical Performance: MC74AC139DR2G provides enhanced output current capability (24mA vs. 1mA/20mA) and extended operating temperature range (-40°C to 85°C vs. 0°C to 70°C), supporting broader application requirements
• Supply Voltage: MC74AC139DR2G operates across 2V to 6V, encompassing the 74F139SCX operating range of 4.5V to 5.5V

Frequently Asked Questions (FAQ)

Q: Can MC74AC139DR2G directly replace 74F139SCX in existing designs?

A: Yes. Both parts share identical circuit configuration (1 x 2:4 decoder/demultiplexer), pinout, and 16-SOIC package. No PCB modifications are required for substitution.

Q: What are the key electrical differences between these parts?

A: MC74AC139DR2G provides higher output current capability (24mA vs. 1mA/20mA) and operates across a wider voltage range (2V to 6V vs. 4.5V to 5.5V). These differences represent performance enhancements suitable for the same applications.

Q: Does the extended temperature range of MC74AC139DR2G affect compatibility?

A: No. The extended operating temperature range (-40°C to 85°C) of MC74AC139DR2G is a superset of the 74F139SCX range (0°C to 70°C). Applications operating within the original temperature limits remain fully compatible.

Q: Are there packaging differences between these parts?

A: No. Both parts use identical 16-SOIC (0.154", 3.90mm Width) surface mount packages with matching pinouts and moisture sensitivity levels.

Q: Why is 74F139SCX classified as obsolete?

A: The 74F logic series has been superseded by more advanced logic families. MC74AC139DR2G from the 74AC series represents the current-generation equivalent with improved electrical characteristics and active manufacturing status.