CD74AC138EE4 Equivalent & Substitute Parts

Part Overview

The CD74AC138EE4 is a 3-line to 8-line inverting decoder/demultiplexer manufactured by Texas Instruments. This logic component decodes three binary input lines into eight mutually exclusive outputs, functioning as a 1 x 3:8 decoder/demultiplexer in a 16-pin DIP package. The part is currently in active production status with 852 units available in new original inventory. Substitute parts are identified when equivalent electrical and mechanical parameters are maintained, particularly when the original part becomes unavailable or when alternative sourcing is required for supply chain optimization.

Substiute Parts

CD74AC138EE4

Texas InstrumentsIn Stock: 930CD74AC138EE4 Datasheet

Current PartRFQ

CD74AC138E

Harris CorporationIn Stock: 1604CD74AC138E Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the CD74AC138EE4 is determined by strict equivalence across the following critical parameters:

Electrical Parameters (Must Match):

• Decoder/demultiplexer circuit configuration: 1 x 3:8
• Output current specifications: 24mA high, 24mA low
• Supply voltage range: 1.5V ~ 5.5V
• Operating temperature range: -55°C ~ 125°C
• Single supply voltage source architecture

Mechanical Parameters (Must Match):

• Package type: 16-DIP (0.300", 7.62mm)
• Mounting type: Through Hole
• Pin count and pitch compatibility

Compliance Parameters (Considered):

• RoHS status and regulatory compliance
• Product availability and lifecycle status

The CD74AC138E from Harris Corporation meets all electrical and mechanical parameter requirements for substitution. However, product status and compliance differences must be evaluated for specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

CD74AC138EE4 (Texas Instruments) - Primary Selection: This part is recommended for new designs and applications requiring current production availability. The part maintains active product status with ROHS3 compliance, meeting modern regulatory requirements. Current inventory of 852 units supports immediate procurement needs.

CD74AC138E (Harris Corporation) - Substitute Selection: This part provides electrical and mechanical equivalence to the CD74AC138EE4 and is suitable for applications where legacy component sourcing is acceptable. The part is classified as obsolete and does not meet ROHS3 compliance standards. Use of this substitute is limited to applications where RoHS non-compliance is permissible and where supply chain constraints necessitate alternative sourcing. The higher available inventory (1525 units) may support specific procurement scenarios.

Selection Criteria:

• For new designs and RoHS-compliant applications: Select CD74AC138EE4
• For legacy system maintenance or non-regulated applications: CD74AC138E is electrically and mechanically equivalent
• Both parts share identical electrical performance and package specifications
• Compliance status and product lifecycle are the primary differentiators

Frequently Asked Questions (FAQ)

Q: Can CD74AC138E be used as a direct replacement for CD74AC138EE4?

A: Yes, from an electrical and mechanical standpoint. Both parts feature identical 1 x 3:8 decoder/demultiplexer configuration, 24mA output current specifications, 1.5V to 5.5V supply voltage range, -55°C to 125°C operating temperature, and 16-DIP through-hole package. However, the CD74AC138E is obsolete and RoHS non-compliant, which may restrict its use in regulated applications.

Q: What are the key parameters that determine substitution eligibility?

A: Substitution is determined by equivalence in circuit configuration (1 x 3:8), output current (24mA/24mA), supply voltage range (1.5V ~ 5.5V), operating temperature (-55°C ~ 125°C), and package type (16-DIP through-hole). Any deviation in these parameters disqualifies a part from substitution.

Q: Why is the CD74AC138E listed as obsolete?

A: The CD74AC138E from Harris Corporation is classified as obsolete in current component databases. This designation indicates the part is no longer in active production. The CD74AC138EE4 from Texas Instruments remains in active production status.

Q: Are there any compliance differences between these parts?

A: Yes. The CD74AC138EE4 is ROHS3 compliant, meeting current environmental and regulatory standards. The CD74AC138E is RoHS non-compliant. Applications subject to RoHS regulations must use the CD74AC138EE4.

Q: Do both parts use the same pinout and package dimensions?

A: Yes. Both parts use a 16-pin DIP package with 0.300" (7.62mm) pitch and are mounted through-hole. Pin configuration and spacing are identical, allowing direct PCB compatibility.

Q: What inventory considerations should influence part selection?

A: The CD74AC138EE4 has 852 units in current stock, while the CD74AC138E has 1525 units available. For immediate procurement, either part may be suitable depending on compliance requirements. For long-term supply chain planning, the active status of the CD74AC138EE4 ensures continued availability.