CDC391DR Clock Fanout Buffer Equivalent & Substitute Parts

Part Overview

The CDC391DR is a Clock Fanout Buffer (Distribution) IC manufactured by Texas Instruments, designed for 1:6 clock distribution at frequencies up to 100 MHz. This component features TTL-level input and output, operates within a 4.75V to 5.25V supply voltage range, and is housed in a 16-SOIC surface mount package.

The CDC391DR is classified as obsolete. Identifying equivalent substitute parts is necessary to maintain design continuity, ensure supply chain reliability, and support ongoing production or maintenance of systems utilizing this component.

Substiute Parts

CDC391DR

Texas InstrumentsIn Stock: 4879CDC391DR Datasheet

Current PartRFQ

CDC328ADR

Texas InstrumentsIn Stock: 782CDC328ADR Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the CDC391DR is determined by strict equivalence across the following critical parameters:

• Functional Type: Fanout Buffer (Distribution) IC with 1:6 input-to-output ratio
• Logic Levels: TTL input and TTL output (no differential signaling)
• Maximum Frequency: 100 MHz minimum capability
• Supply Voltage Range: 4.75V to 5.25V
• Package: 16-SOIC (0.154", 3.90mm Width) surface mount
• Operating Temperature Range: -40°C to 85°C minimum

The CDC328ADR meets all these criteria and qualifies as a parametric equivalent. Substitution is valid when these parameters align exactly with application requirements.

Parameter Comparison

Engineering Selection Recommendations

The CDC328ADR is the qualified substitute for the CDC391DR based on complete parametric equivalence across all electrical and mechanical specifications. The CDC328ADR maintains identical functional performance, package footprint, and operating characteristics while offering the advantage of active product status from Texas Instruments.

The CDC328ADR carries ROHS3 compliance and REACH unaffected status, matching the regulatory certifications of the original part. Moisture Sensitivity Level (MSL) is rated at 1 (Unlimited) for both components, indicating no special handling requirements during storage or assembly.

Selection of the CDC328ADR eliminates obsolescence risk while preserving full design compatibility with existing PCB layouts and circuit implementations designed for the CDC391DR.

Frequently Asked Questions (FAQ)

Q: Can the CDC328ADR be used as a direct replacement for the CDC391DR?

A: Yes. The CDC328ADR is a parametric equivalent with identical electrical specifications, logic levels, frequency rating, supply voltage range, operating temperature range, and 16-SOIC package dimensions. Direct substitution is valid for applications requiring these specifications.

Q: What is the primary difference between these two parts?

A: The CDC391DR is classified as obsolete, while the CDC328ADR is active. Both parts are functionally and electrically identical. The CDC328ADR is available from Texas Instruments and represents the current equivalent for new designs and ongoing production.

Q: Are there packaging differences between CDC391DR and CDC328ADR?

A: No. Both components use the 16-SOIC (0.154", 3.90mm Width) surface mount package. PCB footprints are identical, and no layout modifications are required for substitution.

Q: Do these parts have different moisture sensitivity requirements?

A: No. Both the CDC391DR and CDC328ADR are rated MSL 1 (Unlimited), indicating no moisture sensitivity restrictions. Standard handling and storage practices apply to both components.

Q: Are there compliance or certification differences?

A: Both parts carry ROHS3 compliance and REACH unaffected status. Regulatory certifications are equivalent, and substitution does not introduce compliance concerns.

Q: What is the maximum clock frequency supported by the CDC328ADR?

A: The CDC328ADR supports clock frequencies up to 100 MHz, identical to the CDC391DR specification.