VLZ33C-GS08 Equivalent & Substitute Parts

Part Overview

The VLZ33C-GS08 is a Zener diode rated at 31.7 V nominal voltage with 500 mW power dissipation in a SOD-80 QuadroMELF surface mount package. Manufactured by Vishay General Semiconductor - Diodes Division, this component is classified as Obsolete. Due to its obsolete status and limited availability relative to active alternatives, identifying equivalent substitute parts is necessary for ongoing design support and production continuity. The part carries AEC-Q101 automotive qualification and ROHS3 compliance.

Substiute Parts

VLZ33C-GS08

Vishay General Semiconductor - Diodes DivisionIn Stock: 1037VLZ33C-GS08 Datasheet

Current PartRFQ

TLZ33C-GS08

Vishay General Semiconductor - Diodes DivisionIn Stock: 40427TLZ33C-GS08 Datasheet

DirectRFQ

1N4121UR-1

Microchip TechnologyIn Stock: 9941N4121UR-1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the VLZ33C-GS08 is determined by the following critical parameters:

Electrical Compatibility Criteria:

• Zener voltage within acceptable tolerance of 31.7 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
• Surface mount footprint compatibility

Compliance & Status Criteria:

• Active product status preferred for long-term availability
• ROHS3 compliance maintained
• Automotive grade and AEC-Q101 qualification preferred

The substitute parts identified meet the electrical and mechanical requirements for direct functional replacement while addressing the obsolete status of the main part.

Parameter Comparison

Engineering Selection Recommendations

TLZ33C-GS08 (Primary Substitute): The TLZ33C-GS08 is the preferred substitute for the VLZ33C-GS08. Both parts are manufactured by Vishay General Semiconductor and share identical electrical specifications: 500 mW power rating, 65 Ohms maximum impedance, and -65°C to 175°C operating temperature range. The zener voltage differs by 1.3 V (33 V versus 31.7 V nominal), which falls within acceptable tolerance for most circuit applications. The TLZ33C-GS08 maintains ROHS3 compliance and offers significantly higher inventory availability (40,400 pieces). Both parts use SOD-80 package variants with compatible surface mount footprints. The TLZ33C-GS08 is an active product, ensuring long-term supply continuity.

1N4121UR-1 (Secondary Substitute): The 1N4121UR-1 manufactured by Microchip Technology provides an alternative substitute with identical 500 mW power rating and -65°C to 175°C operating temperature range. The zener voltage is 33 V, matching the TLZ33C-GS08. However, this part exhibits higher impedance (200 Ohms versus 65 Ohms) and uses a different package format (DO-213AA versus SOD-80). The 1N4121UR-1 is RoHS non-compliant, which may restrict its use in applications requiring RoHS compliance. This part is suitable only when package footprint differences are acceptable and RoHS compliance is not required.

Frequently Asked Questions (FAQ)

Q: Can the TLZ33C-GS08 directly replace the VLZ33C-GS08 without circuit modification?

A: The TLZ33C-GS08 is electrically compatible for most applications. The zener voltage difference of 1.3 V (31.7 V to 33 V) is within typical circuit tolerance margins. Both parts share identical power ratings (500 mW), impedance (65 Ohms), and operating temperature ranges. The SOD-80 package variants are mechanically compatible. Circuit validation is required only if the application has strict zener voltage tolerance requirements below ±4%.

Q: What is the primary difference between the TLZ33C-GS08 and VLZ33C-GS08?

A: The primary differences are product status and packaging variant. The VLZ33C-GS08 is obsolete and uses SOD-80 QuadroMELF packaging, while the TLZ33C-GS08 is active and uses SOD-80 MiniMELF packaging. Electrically, both parts are nearly identical with the exception of zener voltage (31.7 V versus 33 V nominal). The TLZ33C-GS08 offers superior availability and long-term supply assurance.

Q: Why is the 1N4121UR-1 listed as a secondary substitute?

A: The 1N4121UR-1 meets the core electrical requirements (500 mW power, 33 V zener voltage, -65°C to 175°C operating range) but introduces two significant limitations. First, it uses DO-213AA packaging instead of SOD-80, requiring PCB footprint redesign. Second, it is RoHS non-compliant, which disqualifies it from applications requiring RoHS certification. Use this part only when package changes are feasible and RoHS compliance is not mandated.

Q: Are there package compatibility concerns between SOD-80 QuadroMELF and SOD-80 MiniMELF?

A: Both variants are SOD-80 package family members with compatible surface mount footprints. The QuadroMELF and MiniMELF designations refer to internal lead frame configurations, not external dimensions. PCB footprints designed for SOD-80 QuadroMELF accept SOD-80 MiniMELF components without modification.

Q: Does the TLZ33C-GS08 maintain automotive qualification?

A: The provided specifications for the TLZ33C-GS08 do not include automotive grade or AEC-Q101 qualification data. The VLZ33C-GS08 carries AEC-Q101 qualification. For automotive applications requiring AEC-Q101 certification, confirm qualification status with the manufacturer before substitution.

Q: What is the significance of the reverse leakage current difference between these parts?

A: The VLZ33C-GS08 specifies 40 µA reverse leakage at 29.4 V, while the TLZ33C-GS08 specifies 40 nA at the same voltage. The TLZ33C-GS08 exhibits significantly lower leakage (1000:1 ratio). Lower leakage current reduces power consumption in standby conditions and improves circuit stability. This difference is advantageous for most applications and does not prevent substitution.

Q: Is the impedance difference between TLZ33C-GS08 (65 Ohms) and 1N4121UR-1 (200 Ohms) significant?

A: Impedance affects transient response and voltage regulation characteristics. The 1N4121UR-1 impedance of 200 Ohms is 3.08 times higher than the TLZ33C-GS08 impedance of 65 Ohms. Higher impedance results in slower transient response and reduced voltage regulation performance. This difference is significant for high-frequency or fast-transient applications. The TLZ33C-GS08 is preferred when impedance performance is critical.