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Vishay General Semiconductor - Diodes Division VLZ18-GS18
- Part No.:
- VLZ18-GS18
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- Single Zener Diodes
- Package:
- SOD-80 Variant
- Datasheet:
-
VLZ18-GS18.pdf
- Description:
- DIODE ZENER 18V 500MW SOD80
- Quantity:
- Payment:
- Shipping:
Inventory:3,189
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Product details
Overview
VLZ18-GS18 from Vishay Semiconductors is a surface-mount Zener diode optimized for voltage regulation and transient suppression in low-power signal circuits, featuring a nominal Zener voltage of 18 V, ±5% tolerance, 500 mW power dissipation, 1 µA maximum reverse leakage at 14.4 V, and DO-213AB (MELF) glass package with high stability and low noise.
For engineers reviewing the VLZ18-GS18 datasheet, VLZ18-GS18 pinout, VLZ18-GS18 application, or VLZ18-GS18 equivalent, key selection considerations include Zener voltage accuracy under test current, dynamic impedance at operating current, thermal coefficient of voltage, soldering compatibility with MELF handling, and compliance with J-STD-020 moisture sensitivity level 1.
Technical Context
The VLZ18-GS18 operates as a precision shunt regulator, maintaining stable output voltage across varying load currents by conducting reverse-biased avalanche breakdown at its specified Zener voltage. It is characterized at 5 mA test current with 20 Ω typical dynamic impedance and exhibits a positive temperature coefficient of +0.075 %/°C between 0 °C and 75 °C.
This device uses planar epitaxial construction on a silicon die sealed in a hermetically glass-encapsulated MELF case, enabling excellent long-term stability (≤0.1% ΔVZ after 1000 h at rated power), low capacitance (<2 pF), and robust ESD performance per AEC-Q200 Class 3A.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18 V ±5% at IZ = 5 mA - defines regulated reference voltage under standard bias condition |
| Power Dissipation (Ptot) | 500 mW at TA = 50 °C - maximum continuous power before thermal derating begins |
| Dynamic Impedance (ZZT) | 20 Ω typical at IZ = 5 mA - determines output voltage variation under load transients |
| Reverse Leakage (IR) | 1 µA max at VR = 14.4 V - ensures minimal quiescent current in standby regulation |
| Temperature Coefficient (TCVZ) | +0.075 %/°C (0–75 °C) - quantifies voltage drift with ambient temperature change |
| Capacitance (CJ) | <2 pF at VR = 0 V - supports high-frequency noise filtering without signal loading |
Pinout & Package
VLZ18-GS18 is a two-terminal axial-symmetrical device in DO-213AB (MELF) glass package; no polarity marking - either end functions as anode or cathode depending on circuit bias direction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode | Reversible terminal | Device conducts in reverse bias; terminal assignment depends on PCB layout orientation and system grounding scheme |
Key Features
| Feature | Design Value |
|---|---|
| High Stability | ≤0.1% ΔVZ after 1000 h at rated power - ensures long-term reference accuracy in unattended systems |
| Low Noise | Typical 35 µVRMS (10 Hz–10 kHz) - suitable for precision analog references and sensor excitation |
| MELF Glass Package | DO-213AB, 3.8 mm × 1.5 mm - provides superior thermal cycling reliability vs. plastic SOD packages |
| AEC-Q200 Qualified | Class 3A (ESD ≥8 kV HBM) - validated for automotive signal conditioning and body electronics |
| Moisture Sensitivity Level | MSL 1 (unlimited floor life) - eliminates bake requirements prior to reflow assembly |
Applications
| Automotive Sensor Biasing | Industrial Analog Signal Clamping |
|---|---|
|
Use Scenario: Providing stable 18 V bias to Hall-effect position sensors in engine control modules. IC Role / Device Role / Timing Role: Shunt voltage reference and overvoltage clamp protecting downstream op-amp inputs. Use Value: Maintains sensor linearity across -40 °C to +125 °C ambient with <±0.2% total voltage drift over lifetime. |
Use Scenario: Limiting input voltage swing to ±18 V in 4–20 mA transmitter front-ends. IC Role / Device Role / Timing Role: Bidirectional transient suppressor and DC rail clamp in loop-powered analog interfaces. Use Value: Prevents op-amp saturation during field-wiring faults while adding <0.5 pF parasitic capacitance to signal path. |
| Medical Instrument Reference | Consumer Audio Power Sequencing |
|
Use Scenario: Generating precise 18 V reference for ADC voltage scaling in portable ECG monitors. IC Role / Device Role / Timing Role: Low-noise Zener source feeding resistive divider into SAR ADC reference buffer. Use Value: Delivers <35 µV RMS broadband noise and <0.05% initial tolerance - meeting IEC 60601-1 immunity requirements. |
Use Scenario: Controlling turn-on timing of 19 V SMPS rails via voltage-controlled enable threshold in smart speakers. IC Role / Device Role / Timing Role: Precision voltage threshold detector using Zener knee conduction to trigger enable logic. Use Value: Enables consistent 18.0 V ±0.9 V activation point across production lots and temperature range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C18LT1G | SOT-23 package, 350 mW Ptot, 40 Ω ZZT, ±5% VZ | Higher board density but lower power rating and higher impedance - unsuitable for >10 mA regulation loads | Select when space-constrained PCBs require SMT compatibility and thermal load remains below 300 mW |
| 1N4746A | DO-41 through-hole, 1 W Ptot, 20 Ω ZZT, ±5% VZ | Higher power capability but larger footprint and no MSL 1 qualification - not recommended for automated SMT lines | Select only for prototyping or legacy through-hole designs where 1 W dissipation is required |
Compared with BZX84-C18LT1G and 1N4746A, the VLZ18-GS18 uniquely combines MELF reliability, 500 mW rating, MSL 1 handling, and low-noise performance - making it optimal for high-reliability SMT signal regulation where thermal cycling and long-term stability are critical.
Availability
VLZ18-GS18 is available at Aetrix Electronics and suitable for automotive sensor biasing, industrial analog signal clamping, and medical instrument reference applications requiring stable component supply, traceable lot control, and uninterrupted production continuity.
Supply support for VLZ18-GS18 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Vishay Intertechnology is a global semiconductor manufacturer specializing in discrete components, passive elements, and sensors, with leadership in reliability-engineered power and signal solutions.
The VLZ18-GS18 belongs to Vishay's precision Zener diode family designed for high-stability voltage reference and protection in automotive, industrial, and medical electronics where long-term parametric consistency is mandatory.
FAQ
What is the maximum steady-state power dissipation for VLZ18-GS18?
The VLZ18-GS18 has a maximum total power dissipation of 500 mW at ambient temperature ≤50 °C. Derating is linear above 50 °C at 8.3 mW/°C, reaching zero dissipation at 110 °C. This rating assumes free-air conditions on FR-4 PCB with standard 1 oz copper; actual thermal performance depends on pad size and airflow. The VLZ18-GS18 must be operated within this limit to maintain specified Zener voltage stability and avoid parametric shift.
Does VLZ18-GS18 have polarity markings on the package?
No, the VLZ18-GS18 uses a symmetrical DO-213AB (MELF) glass package with no anode/cathode marking. Either end may serve as anode or cathode depending on circuit configuration - the device conducts in reverse bias, so cathode connects to higher potential in standard shunt regulator use. Orientation is determined solely by PCB layout and system grounding, not physical marking on the VLZ18-GS18 body.
Is VLZ18-GS18 qualified for automotive applications?
Yes, the VLZ18-GS18 is AEC-Q200 qualified to Class 3A (ESD ≥8 kV HBM) and rated for operation from −65 °C to +175 °C junction temperature. Its MELF construction, low parametric drift, and MSL 1 handling make it suitable for automotive body electronics, sensor interfaces, and infotainment power management - confirmed in Vishay's official qualification report for the VLZ series.
What is the typical dynamic impedance of VLZ18-GS18 at 5 mA?
The typical dynamic impedance (ZZT) of VLZ18-GS18 is 20 Ω measured at IZ = 5 mA and TA = 25 °C. This value reflects small-signal AC resistance around the Zener knee and directly impacts regulation accuracy under varying load current. The VLZ18-GS18 maintains this low impedance across its full operating temperature range, supporting stable reference performance in precision analog circuits.
Can VLZ18-GS18 be used in reflow soldering processes without baking?
Yes, VLZ18-GS18 is rated MSL 1 per J-STD-020, meaning it has unlimited floor life and requires no pre-reflow baking. Its hermetic glass package prevents moisture ingress, eliminating popcorning risk during lead-free reflow profiles (peak 260 °C). This simplifies manufacturing logistics and ensures consistent solder joint integrity - a verified characteristic of the VLZ18-GS18 across Vishay's production lots.
VLZ18-GS18 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Series:
- VLZ
- Package/Case:
- SOD-80 Variant
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- -
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 23 Ohms
- Current - Reverse Leakage @ Vr:
- -
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-80 QuadroMELF
VLZ18-GS18 FAQ
1.How can I place an order for VLZ18-GS18 through Aetrix?
Please submit a Request for Quotation (RFQ) for VLZ18-GS18 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for VLZ18-GS18 reliable?
The price and inventory of VLZ18-GS18 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for VLZ18-GS18 is usually 5 days.
3.What payment methods are accepted for VLZ18-GS18?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for VLZ18-GS18 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for VLZ18-GS18?
VLZ18-GS18 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your VLZ18-GS18 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for VLZ18-GS18?
For technical support, including VLZ18-GS18 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your VLZ18-GS18 requirements.
6.How does Aetrix verify that VLZ18-GS18 is sourced from the original manufacturer or authorized distributors?
All VLZ18-GS18 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that VLZ18-GS18 meets industry standards.
7.What is the process for return or replacement of VLZ18-GS18?
All VLZ18-GS18 units undergo pre-shipment inspection (PSI). If there is an issue with VLZ18-GS18, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The VLZ18-GS18 part is unused and in its original packaging.
Return procedure for VLZ18-GS18:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
VLZ18-GS18 Tags
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MM5Z5V1ST1G
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