VLZ18C-GS18 Equivalent & Substitute Parts

Part Overview

The VLZ18C-GS18 is a Zener diode rated at 17.88 V nominal with 500 mW power dissipation in a surface mount SOD-80 QuadroMELF package. Manufactured by Vishay General Semiconductor - Diodes Division, this component is classified as Obsolete, necessitating identification of equivalent substitute parts for ongoing design requirements and procurement needs. The part carries AEC-Q101 automotive qualification and ROHS3 compliance.

Substiute Parts

VLZ18C-GS18

Vishay General Semiconductor - Diodes DivisionIn Stock: 1075VLZ18C-GS18 Datasheet

Current PartRFQ

TLZ18C-GS18

Vishay General Semiconductor - Diodes DivisionIn Stock: 1121TLZ18C-GS18 Datasheet

DirectRFQ

1N4112UR-1

Microchip TechnologyIn Stock: 7771N4112UR-1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the VLZ18C-GS18 is determined by the following critical parameters:

Electrical Compatibility Criteria:

• Zener voltage within acceptable tolerance of 17.88 V nominal
• Power dissipation rating of 500 mW minimum
• Operating temperature range of -65°C to 175°C minimum
• Surface mount configuration

Mechanical Compatibility Criteria:

• SOD-80 package family compatibility
• Pin configuration and footprint alignment

Compliance Criteria:

• ROHS3 compliance or equivalent regulatory status
• Automotive grade qualification (AEC-Q101 preferred)

The substitute parts identified meet these criteria with variations in impedance, reverse leakage current, and forward voltage characteristics that remain within acceptable operational parameters for zener diode applications.

Parameter Comparison

Engineering Selection Recommendations

TLZ18C-GS18 (Vishay General Semiconductor - Diodes Division)

The TLZ18C-GS18 is the primary substitute for the VLZ18C-GS18. Both parts are manufactured by Vishay General Semiconductor and share identical electrical specifications including 500 mW power rating, 23 Ohms maximum impedance, and -65°C to 175°C operating temperature range. The TLZ18C-GS18 operates at 18 V nominal zener voltage compared to 17.88 V, representing a 0.67% variance. The TLZ18C-GS18 maintains ROHS3 compliance and carries Active product status, ensuring long-term availability. The primary difference is package variant designation (MiniMELF versus QuadroMELF within the SOD-80 family) and significantly improved reverse leakage current (40 nA versus 40 µA). This part is suitable for applications where the slightly higher zener voltage and lower leakage current are acceptable.

1N4112UR-1 (Microchip Technology)

The 1N4112UR-1 is an alternative substitute manufactured by Microchip Technology. This part meets the 500 mW power requirement and operates within the -65°C to 175°C temperature range. The 1N4112UR-1 operates at 18 V nominal zener voltage with ±5% tolerance specification. Notable differences include higher impedance (100 Ohms versus 23 Ohms), lower forward voltage (1.1 V versus 1.5 V at 200 mA), and RoHS non-compliance status. The package is DO-213AA rather than SOD-80 variant, requiring PCB footprint verification. This part is suitable for applications where RoHS compliance is not a requirement and impedance variation is acceptable.

For applications requiring automotive qualification and ROHS3 compliance, the TLZ18C-GS18 is the recommended substitute. For applications with less stringent compliance requirements, the 1N4112UR-1 provides an alternative with different electrical characteristics.

Frequently Asked Questions (FAQ)

Q: Can the TLZ18C-GS18 directly replace the VLZ18C-GS18 on existing PCBs?

A: The TLZ18C-GS18 uses SOD-80 MiniMELF packaging while the VLZ18C-GS18 uses SOD-80 QuadroMELF packaging. Both are SOD-80 variants but have different physical dimensions and footprints. PCB layout verification is required before substitution.

Q: What is the significance of the zener voltage difference between 17.88 V and 18 V?

A: The 0.67% difference in nominal zener voltage falls within typical circuit tolerance margins for voltage regulation applications. The actual operating point depends on circuit design and load conditions.

Q: Why does the 1N4112UR-1 have higher impedance than the other options?

A: Impedance is a characteristic of the diode's internal structure and manufacturing process. Higher impedance affects voltage regulation performance under varying load conditions. Selection depends on specific circuit requirements for voltage stability.

Q: Is the reverse leakage current difference between 40 µA and 40 nA significant?

A: The TLZ18C-GS18 exhibits significantly lower reverse leakage current (40 nA) compared to the VLZ18C-GS18 (40 µA). This represents improved leakage performance and is generally beneficial for circuit operation, particularly in low-power applications.

Q: What does RoHS non-compliance mean for the 1N4112UR-1?

A: RoHS non-compliance indicates the part may contain restricted substances such as lead. Selection of this part requires verification that the application and end-use market permit non-compliant components.

Q: Are all three parts suitable for automotive applications?

A: The VLZ18C-GS18 and TLZ18C-GS18 are automotive-grade components. The 1N4112UR-1 does not carry automotive qualification designation. Automotive applications should prioritize the TLZ18C-GS18 for compliance with automotive standards.

Q: What is the difference between SOD-80 QuadroMELF and SOD-80 MiniMELF?

A: Both are SOD-80 package variants with different physical dimensions. QuadroMELF is larger than MiniMELF. PCB footprints are not interchangeable without layout modification.