FLZ18VC Equivalent & Substitute Parts

Part Overview

The FLZ18VC is a Zener diode manufactured by onsemi, rated at 17.9 V nominal with 500 mW power dissipation in a surface mount SOD-80 package. This component is classified as obsolete, necessitating identification of equivalent substitute parts for ongoing design requirements and procurement needs. Substitute parts must maintain electrical compatibility across voltage regulation, power handling, and thermal operating ranges while accommodating the surface mount package format.

Substiute Parts

FLZ18VC

onsemiIn Stock: 2176FLZ18VC Datasheet

Current PartRFQ

BZV55-B18,115

Nexperia USA Inc.In Stock: 2184BZV55-B18,115 Datasheet

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BZV55-C18,115

NXP SemiconductorsIn Stock: 25782BZV55-C18,115 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FLZ18VC are qualified based on the following electrical and mechanical parameters:

Voltage Compatibility: Substitute Zener diodes must operate within the 17.9 V nominal specification. The BZV55-B18,115 and BZV55-C18,115 both specify 18 V nominal, representing a 0.1 V deviation (0.56% variance) from the original specification, which falls within acceptable tolerance bands for voltage regulation applications.

Power Dissipation: All substitute candidates maintain the 500 mW maximum power rating, ensuring thermal and electrical equivalence in circuit operation.

Package Format: Substitute parts must utilize surface mount technology with DO-213AC, MINI-MELF, or SOD-80 package designations to ensure mechanical compatibility with existing PCB layouts and assembly processes.

Operating Temperature Range: Substitute parts must support the thermal operating envelope. The BZV55 series extends to 200°C maximum, exceeding the original -65°C to 175°C range and providing enhanced thermal margin.

Moisture Sensitivity: All candidates maintain MSL 1 (Unlimited) classification, ensuring equivalent moisture handling during storage and assembly.

Parameter Comparison

Engineering Selection Recommendations

BZV55-B18,115 (Nexperia USA Inc.): This substitute offers active product status with ROHS3 compliance certification. The ±2% tolerance specification provides tighter voltage regulation than the original FLZ18VC (±3%), and the extended operating temperature range to 200°C enhances thermal performance margin. The 45 Ohm impedance represents a 2.32x increase over the original specification; circuit designs must accommodate this impedance characteristic in voltage regulation applications.

BZV55-C18,115 (NXP Semiconductors): This substitute maintains active product status with extended operating temperature range to 200°C. The ±5% tolerance specification is broader than the original FLZ18VC (±3%), suitable for applications with relaxed voltage regulation requirements. Inventory availability of 25,760 pieces provides supply security. The 45 Ohm impedance characteristic applies identically to the BZV55-B18,115 variant.

Both substitute parts satisfy the core electrical and mechanical requirements for direct replacement in surface mount applications. Selection between BZV55-B18,115 and BZV55-C18,115 depends on tolerance requirements: the B-variant (±2%) for precision voltage regulation, and the C-variant (±5%) for general-purpose applications with broader tolerance acceptance.

Frequently Asked Questions (FAQ)

Q: Can the BZV55-B18,115 and BZV55-C18,115 be used interchangeably with the FLZ18VC?

A: Both BZV55 variants are electrically compatible substitutes for the FLZ18VC in surface mount applications. The primary difference is voltage tolerance: BZV55-B18,115 specifies ±2% tolerance, while BZV55-C18,115 specifies ±5% tolerance. Selection depends on circuit tolerance requirements.

Q: What is the significance of the impedance difference between the FLZ18VC (19.4 Ohms) and the BZV55 series (45 Ohms)?

A: Impedance affects voltage regulation stability and transient response. The higher impedance of the BZV55 series (45 Ohms) results in slightly reduced regulation performance compared to the FLZ18VC (19.4 Ohms). Circuit designs must account for this characteristic in applications requiring tight voltage stability.

Q: Are the BZV55-B18,115 and BZV55-C18,115 compatible with existing PCB layouts designed for the FLZ18VC?

A: Yes. All three parts utilize identical package formats (DO-213AC, MINI-MELF, SOD-80) and surface mount technology, ensuring mechanical and footprint compatibility with existing PCB designs.

Q: What is the operating temperature advantage of the BZV55 substitutes?

A: The BZV55 series extends the maximum operating temperature to 200°C, compared to the FLZ18VC maximum of 175°C. This provides a 25°C thermal margin, beneficial for applications operating in elevated temperature environments.

Q: Why is the FLZ18VC classified as obsolete?

A: Obsolete status indicates the part is no longer manufactured by onsemi. The BZV55-B18,115 and BZV55-C18,115 are active products from Nexperia and NXP, respectively, ensuring long-term availability and supply continuity.

Q: How do the reverse leakage current specifications compare?

A: The FLZ18VC specifies 133 nA @ 13 V, while both BZV55 variants specify 50 nA @ 12.6 V. The BZV55 series exhibits lower reverse leakage, indicating improved leakage performance characteristics.

Q: What compliance certifications apply to the substitute parts?

A: The BZV55-B18,115 carries ROHS3 compliance certification. Both BZV55 variants maintain REACH Unaffected status and EAR99 export classification, consistent with the original FLZ18VC.