CLL4746A BK PBFREE Equivalent & Substitute Parts

Part Overview

The CLL4746A BK PBFREE is an 18 V, 1 W Zener diode manufactured by Central Semiconductor Corp, designed for surface mount applications in the MELF package format. This component is classified as an active product with full RoHS3 compliance and unlimited moisture sensitivity rating. Equivalent and substitute parts are identified to support procurement flexibility, inventory management, and design continuity when the primary part becomes unavailable or when alternative specifications better suit application requirements.

Substiute Parts

CLL4746A BK PBFREE

Central Semiconductor CorpIn Stock: 940CLL4746A BK PBFREE Datasheet

Current PartRFQ

CDLL4471

Microchip TechnologyIn Stock: 1161CDLL4471 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of Zener diodes is determined by strict alignment of electrical and mechanical parameters. The primary criteria for equivalent functionality are:

Critical Parameters (Must Match):

• Zener voltage nominal value: 18 V
• Tolerance specification: ±5%
• Package format: DO-213AB / MELF surface mount
• Mounting type: Surface mount

Secondary Parameters (Allow Variation Within Limits):

• Power rating: Substitute may equal or exceed the original specification
• Impedance: Lower impedance values indicate improved performance characteristics
• Reverse leakage current: Lower values indicate superior device quality
• Forward voltage: Variations within typical operating ranges are acceptable
• Operating temperature range: Substitute must cover or exceed the original range

The CDLL4471 manufactured by Microchip Technology meets all critical parameters and provides enhanced electrical characteristics in secondary parameters, qualifying it as a direct substitute for the CLL4746A BK PBFREE.

Parameter Comparison

Engineering Selection Recommendations

CLL4746A BK PBFREE Selection Criteria:

• Applications requiring RoHS3 compliance certification
• Designs operating at maximum ambient temperatures approaching 200°C
• Procurement scenarios where Central Semiconductor Corp inventory availability is prioritized
• Systems where documented RoHS3 compliance documentation is mandatory for regulatory submission

CDLL4471 Selection Criteria:

• Applications where enhanced electrical performance characteristics provide system margin
• Designs where lower impedance and reduced reverse leakage current improve circuit stability
• Procurement scenarios where Microchip Technology supply chain availability is preferred
• Applications where maximum operating temperature of 175°C is sufficient for thermal requirements
• Note: CDLL4471 is RoHS non-compliant; verify regulatory requirements before selection

Thermal Consideration: The CLL4746A BK PBFREE supports operation to 200°C, while the CDLL4471 is rated to 175°C. Applications requiring sustained operation above 175°C must retain the original CLL4746A BK PBFREE specification.

Frequently Asked Questions (FAQ)

Q: Can CDLL4471 be used as a direct replacement for CLL4746A BK PBFREE in all applications?

A: CDLL4471 is electrically compatible for applications where the maximum operating temperature does not exceed 175°C. The substitute provides superior electrical characteristics (lower impedance, reduced reverse leakage, lower forward voltage). Verify thermal requirements and RoHS compliance status before substitution.

Q: What is the significance of the impedance difference between these parts?

A: Impedance (Zzt) affects the dynamic response of the Zener diode under transient conditions. The CDLL4471 impedance of 11 Ohms is lower than the CLL4746A BK PBFREE impedance of 20 Ohms, indicating improved voltage regulation stability and faster transient response. This is a performance advantage in most applications.

Q: Are the package dimensions identical between CLL4746A BK PBFREE and CDLL4471?

A: Both parts use the DO-213AB / MELF surface mount package format. Mechanical compatibility is confirmed for PCB layout and assembly processes. Verify specific package dimensions with manufacturer datasheets if custom footprint design is required.

Q: Why does CLL4746A BK PBFREE have a higher operating temperature maximum than CDLL4471?

A: Operating temperature range is determined by semiconductor material properties and device construction. The CLL4746A BK PBFREE is rated to 200°C while CDLL4471 is rated to 175°C. This difference reflects manufacturer design specifications and thermal stress testing results for each device.

Q: What is the impact of the reverse leakage current difference?

A: Reverse leakage current (5 µA for CLL4746A BK PBFREE versus 50 nA for CDLL4471) indicates device quality and temperature stability. Lower reverse leakage reduces power dissipation in standby conditions and improves long-term reliability. The CDLL4471 demonstrates superior leakage characteristics.

Q: Is RoHS compliance a critical factor for substitution?

A: RoHS compliance status depends on application regulatory requirements. CLL4746A BK PBFREE is RoHS3 compliant; CDLL4471 is RoHS non-compliant. Verify regulatory requirements for your application before selecting the substitute part.

Q: Can the higher power rating of CDLL4471 (1.5 W vs 1 W) cause circuit problems?

A: No. Higher power rating indicates the device can dissipate more power without thermal damage. This does not affect circuit operation when the actual power dissipation remains within design specifications. The substitute provides additional thermal margin.