NBC12439AFNR2 PLL Clock Generator - Equivalent & Substitute Parts

Part Overview

The NBC12439AFNR2 is a PLL Clock Generator IC manufactured by onsemi, designed for 800MHz maximum frequency operation with PECL output. This component is classified as obsolete, making identification of compatible substitute parts essential for ongoing system support and procurement planning. The part operates across a supply voltage range of 3.135V to 5.25V and is housed in a 28-LCC (J-Lead) surface mount package.

Substiute Parts

NBC12439AFNR2

onsemiIn Stock: 768NBC12439AFNR2 Datasheet

Current PartRFQ

NBC12429AFNR2G

onsemiIn Stock: 1228NBC12429AFNR2G Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the NBC12439AFNR2 is determined by the following critical parameters:

Mandatory Matching Parameters:

• Input Type: Crystal
• Output Type: PECL
• Number of Circuits: 1
• Ratio - Input:Output: 1:1
• Differential - Input:Output: No/Yes
• Package / Case: 28-LCC (J-Lead)
• Mounting Type: Surface Mount
• Voltage - Supply: 3.135V ~ 5.25V
• Operating Temperature: -40°C ~ 85°C

Allowable Variation:

• Frequency - Max: Substitute parts may operate at lower maximum frequencies provided the application requirement does not exceed the substitute's rated frequency

The NBC12429AFNR2G qualifies as a parametric equivalent based on matching all mandatory parameters. The primary difference is the maximum frequency rating of 400MHz versus the original 800MHz specification.

Parameter Comparison

Engineering Selection Recommendations

NBC12429AFNR2G Substitution Criteria:

The NBC12429AFNR2G is a valid substitute for the NBC12439AFNR2 when the application's maximum required frequency does not exceed 400MHz. Both parts share identical functional architecture, package configuration, and electrical operating parameters.

Compliance Considerations:

The NBC12429AFNR2G offers improved environmental compliance with ROHS3 certification, whereas the original NBC12439AFNR2 is RoHS non-compliant. This distinction is relevant for applications subject to regulatory compliance requirements.

Moisture Sensitivity:

The NBC12429AFNR2G carries MSL 3 (168 Hours) compared to MSL 1 (Unlimited) for the original part. This requires adherence to moisture control protocols during storage and handling for the substitute part.

Frequently Asked Questions (FAQ)

Q: Can NBC12429AFNR2G replace NBC12439AFNR2 in all applications?

A: NBC12429AFNR2G is a valid substitute only when the system's maximum required clock frequency does not exceed 400MHz. If your application requires frequencies above 400MHz, this substitute is not suitable.

Q: What is the primary difference between these parts?

A: The maximum frequency specification differs: NBC12439AFNR2 operates to 800MHz, while NBC12429AFNR2G operates to 400MHz. All other electrical and mechanical parameters are identical.

Q: Are there package compatibility concerns?

A: Both parts use the 28-LCC (J-Lead) surface mount package with identical footprint dimensions (11.51x11.51mm). No PCB layout modifications are required for substitution.

Q: Does the RoHS compliance difference affect substitution?

A: RoHS compliance status is a regulatory and procurement consideration. The NBC12429AFNR2G's ROHS3 compliance may be advantageous for applications subject to environmental regulations, while the original part's non-compliance status may restrict its use in certain markets.

Q: What handling precautions apply to NBC12429AFNR2G?

A: NBC12429AFNR2G requires moisture control during storage and handling due to its MSL 3 rating (168-hour limit). The original part's MSL 1 rating allows unlimited storage without moisture precautions.

Q: Are both parts still available for procurement?

A: Both parts are classified as obsolete. NBC12429AFNR2G has higher current inventory availability (1148 units) compared to NBC12439AFNR2 (718 units).