74AC139PC Equivalent & Substitute Parts

Part Overview

The 74AC139PC is a decoder/demultiplexer integrated circuit manufactured by onsemi, featuring a 1 x 2:4 decoder configuration in a 16-DIP package. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing system maintenance, repair, and legacy product support. The 74AC139PC operates as a logic decoder with dual independent circuits, suitable for address decoding and signal routing applications in digital systems.

Substiute Parts

74AC139PC

onsemiIn Stock: 155974AC139PC Datasheet

Current PartRFQ

CD74AC139E

Harris CorporationIn Stock: 1505CD74AC139E Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74AC139PC is determined by the following critical parameters:

• Decoder Configuration: 1 x 2:4 circuit with 2 independent circuits
• Output Current Capability: 24mA high and low output current
• Voltage Supply Range: Single supply operation within compatible voltage windows
• Package Type: 16-DIP through-hole mounting with 0.300" (7.62mm) pitch
• Operating Temperature Range: Functional performance across specified temperature extremes
• Base Product Number: 74AC139 series compatibility

The CD74AC139E qualifies as a direct substitute based on matching decoder configuration, output current specifications, package type, and base product number. Both components share identical circuit topology and pin configuration, enabling direct replacement in 16-DIP socket applications.

Parameter Comparison

Engineering Selection Recommendations

Both the 74AC139PC and CD74AC139E are classified as obsolete products. Selection between these components should be based on the following factors:

Voltage Supply Range Consideration: The CD74AC139E supports a lower minimum supply voltage (1.5V) compared to the 74AC139PC (2V), providing broader compatibility with low-voltage system designs. The CD74AC139E upper limit (5.5V) is slightly lower than the 74AC139PC (6V), which may be relevant for systems operating at elevated supply voltages.

Operating Temperature Range: The CD74AC139E extends the operating temperature range to -55°C ~ 125°C, exceeding the 74AC139PC specification of -40°C ~ 85°C. This extended range is applicable for industrial and extreme-environment applications.

Compliance Status: The CD74AC139E is marked as RoHS non-compliant, whereas the 74AC139PC carries REACH Unaffected status. Regulatory compliance requirements should guide selection in applications subject to environmental directives.

Packaging and Availability: Both components are supplied in 16-PDIP through-hole packages with identical pin configurations, ensuring mechanical and electrical compatibility in existing PCB designs.

Frequently Asked Questions (FAQ)

Q: Can the CD74AC139E directly replace the 74AC139PC in existing designs?

A: Yes. Both components share identical decoder configuration (1 x 2:4), output current specifications (24mA), package type (16-DIP), and pin assignments. Direct socket substitution is electrically and mechanically compatible.

Q: What are the voltage supply differences between these parts?

A: The 74AC139PC operates from 2V to 6V, while the CD74AC139E operates from 1.5V to 5.5V. The CD74AC139E supports lower minimum voltage but has a slightly lower maximum rating. Verify your system's supply voltage falls within the selected component's range.

Q: Are there temperature range limitations I should consider?

A: The 74AC139PC is rated for -40°C to 85°C operation. The CD74AC139E extends this to -55°C to 125°C. If your application requires operation outside the 74AC139PC range, the CD74AC139E may be necessary.

Q: What is the significance of the 16-DIP package specification?

A: The 16-DIP (0.300", 7.62mm) package indicates a through-hole dual inline package with 0.3-inch row spacing. Both components use this identical package, ensuring compatibility with existing PCB footprints and socket designs.

Q: Why are both components marked as obsolete?

A: Obsolete status indicates these components are no longer in active production by their manufacturers. Availability is limited to existing inventory. For new designs, consider evaluating current-generation decoder/demultiplexer alternatives from active product lines.

Q: How do the output current specifications affect circuit design?

A: Both components provide 24mA output current capability for both high and low logic states. This specification determines the maximum load current that can be driven by each output pin. Verify that your load impedance does not exceed this current limit.

Q: What is the significance of the base product number 74AC139?

A: The base product number 74AC139 identifies the core logic function and pin configuration. Variants with different suffixes (PC, E, etc.) represent different manufacturers or packaging options but maintain functional equivalence within the 74AC139 family.