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Nexperia USA Inc. BZX79-B18,133
- Part No.:
- BZX79-B18,133
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
BZX79-B18,133.pdf
- Description:
- DIODE ZENER 18V 400MW ALF2
- Quantity:
- Payment:
- Shipping:
Inventory:5,756
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Product details
Overview
BZX79-B18,133 from Nexperia is a ±2% tolerance Zener voltage regulator diode with nominal 18 V breakdown voltage at 5 mA test current, 50 Ω typical differential resistance, and −2.0 to +16.0 mV/K temperature coefficient. It operates in low-power stabilization circuits requiring stable reference voltages under 500 mW dissipation in SOD27 (DO-35) glass packages.
For engineers reviewing the BZX79-B18,133 datasheet, BZX79-B18,133 pinout, BZX79-B18,133 application, or BZX79-B18,133 equivalent, key selection criteria include Zener voltage tolerance, dynamic impedance, temperature coefficient behavior, reverse leakage at operating bias, and pulse power handling for transient suppression.
Technical Context
This device functions as a two-terminal shunt voltage reference, maintaining regulation by conducting reverse current above its specified Zener voltage. Its operation relies on controlled avalanche breakdown in silicon, with thermal stability governed by the junction temperature-dependent voltage coefficient.
The BZX79-B18,133 exhibits 50 Ω typical differential resistance at IZ = 5 mA, enabling predictable output impedance in feedback networks. Its non-repetitive peak reverse power dissipation is rated at 40 W for 100 μs pulses, supporting transient overvoltage clamping in low-energy protection circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 17.6 V to 18.4 V at IZ = 5 mA - defines precise regulation window for reference design |
| Differential Resistance (rdiff) | 50 Ω typical at IZ = 5 mA - determines output impedance and load regulation error |
| Temperature Coefficient (SZ) | −2.0 to +16.0 mV/K - indicates voltage drift direction and magnitude across operating temperature range |
| Reverse Leakage (IR) | 100 nA max at VR = 12.6 V - ensures minimal quiescent current in high-impedance bias networks |
| Total Power Dissipation (Ptot) | 500 mW at Tamb = 50 °C - sets maximum continuous DC power handling on standard PCB layout |
| Non-repetitive Peak Power (PZSM) | 40 W at tp = 100 μs - supports single-event surge clamping without failure |
| Junction-to-Ambient Rth | 380 K/W - defines thermal rise per watt under standard mounting conditions |
Pinout & Package
Hermetically sealed axial-leaded SOD27 (DO-35) glass package with cathode band marking. Leads are tinned copper-clad steel; body diameter 1.85 mm, length 4.25 mm, lead spacing 25.4 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / reference ground node | Connected to circuit common; establishes reference potential for Zener operation |
| Cathode | Reverse-biased Zener terminal / regulated output node | Provides stabilized voltage relative to anode; marked by colored band on glass body |
Key Features
| Feature | Design Value |
|---|---|
| ±2% Zener voltage tolerance | Enables tight regulation in precision analog references without post-calibration |
| 500 mW total power dissipation | Supports continuous operation in compact PCB layouts without forced cooling |
| 40 W non-repetitive peak power | Clamps ESD and line transients up to 100 μs duration without degradation |
| SOD27 (DO-35) hermetic glass package | Ensures long-term parameter stability and moisture resistance in industrial environments |
| Low 100 nA reverse leakage at 70% VZ | Minimizes current draw in battery-powered or high-impedance sensing circuits |
Applications
| Power Supply Reference | Overvoltage Protection |
|---|---|
Use Scenario: Providing stable 18 V reference for linear regulator feedback or ADC reference divider networks. IC Role / Device Role / Timing Role: Shunt voltage reference establishing precise DC bias point. Use Value: ±2% initial tolerance and low 50 Ω dynamic impedance ensure <±0.5% output variation under load changes. | Use Scenario: Clamping transient surges on 15 V logic supply rails during hot-plug or inductive switching events. IC Role / Device Role / Timing Role: Passive overvoltage clamp limiting rail excursion to ≤18.4 V. Use Value: 40 W peak power rating absorbs 100 μs transients up to 2.2 A without parametric shift. |
| Signal Level Shifting | Current Source Biasing |
Use Scenario: Generating fixed 18 V offset for op-amp input stages interfacing with higher-voltage sensors. IC Role / Device Role / Timing Role: DC level translator defining common-mode voltage for differential amplifiers. Use Value: Low 100 nA leakage prevents loading of high-impedance sensor outputs at room temperature. | Use Scenario: Setting bias current for constant-current LED drivers using resistor-Zener configuration. IC Role / Device Role / Timing Role: Stable voltage source determining emitter/base voltage drop in transistor current mirrors. Use Value: −2.0 to +16.0 mV/K temperature coefficient allows predictable current drift compensation in thermal designs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4746A | 18 V ±5%, 20 Ω typical rdiff, DO-41 package | Higher power (1 W), larger footprint, wider tolerance | Select when higher surge energy handling or board-level robustness outweighs precision needs |
| BZX84-C18 | 18 V ±5%, SOT-23 surface-mount, 500 mW | Smaller footprint, lower thermal mass, no axial leads | Select for space-constrained PCBs where reflow compatibility and automated assembly are required |
Compared with BZX79-B18,133, the 1N4746A offers higher surge capacity but sacrifices voltage precision and package reliability, while the BZX84-C18 enables miniaturization at the cost of reduced thermal stability and tighter process control in production.
Availability
BZX79-B18,133 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and consumer appliance control boards requiring stable component supply with traceable sourcing and long-lifecycle support.
Supply support for BZX79-B18,133 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
Nexperia is a global leader in discrete, logic, and PowerMOS semiconductors, serving automotive, industrial, computing, and consumer markets with high-reliability components.
The BZX79 series belongs to Nexperia's legacy Zener diode product line, engineered for precision voltage regulation and reference stability in cost-sensitive, high-volume applications.
FAQ
What is the maximum continuous forward current for BZX79-B18,133?
The maximum continuous forward current is 250 mA at Tamb = 50 °C. This rating assumes standard PCB mounting with unmetallized pads and 8 mm lead length. Exceeding this value risks thermal runaway due to the device's 380 K/W junction-to-ambient thermal resistance.
How does temperature affect the Zener voltage of BZX79-B18,133?
The temperature coefficient ranges from −2.0 to +16.0 mV/K depending on operating current and junction temperature. At IZ = 5 mA, typical drift is +12.4 mV/K near room temperature, meaning voltage increases ~0.22 V over a 18 °C rise - critical for high-accuracy reference designs.
Can BZX79-B18,133 be used in parallel for higher power handling?
No - Zener diodes exhibit manufacturing variations in breakdown voltage that cause current hogging when paralleled. Even matched units require external balancing resistors, which defeat the purpose of low-impedance regulation. Use a single higher-rated device like 1N4746A instead.
What is the reverse leakage current at 12.6 V (70% of VZ)?
Maximum reverse leakage is 100 nA at VR = 12.6 V and Tj = 25 °C. This value is confirmed in Table 1 of the datasheet for BZX79-B18 under "IR reverse current" conditions, ensuring minimal standby current in high-impedance bias networks.
BZX79-B18,133 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Cut Tape (CT)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±2%
- Power - Max:
- 400 mW
- Impedance (Max) (Zzt):
- 45 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 12.6 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- ALF2
BZX79-B18,133 FAQ
1.How can I place an order for BZX79-B18,133 through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX79-B18,133 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 BZX79-B18,133 reliable?
The price and inventory of BZX79-B18,133 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX79-B18,133 is usually 5 days.
3.What payment methods are accepted for BZX79-B18,133?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX79-B18,133 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX79-B18,133?
BZX79-B18,133 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX79-B18,133 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 BZX79-B18,133?
For technical support, including BZX79-B18,133 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX79-B18,133 requirements.
6.How does Aetrix verify that BZX79-B18,133 is sourced from the original manufacturer or authorized distributors?
All BZX79-B18,133 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 BZX79-B18,133 meets industry standards.
7.What is the process for return or replacement of BZX79-B18,133?
All BZX79-B18,133 units undergo pre-shipment inspection (PSI). If there is an issue with BZX79-B18,133, 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 BZX79-B18,133 part is unused and in its original packaging.
Return procedure for BZX79-B18,133:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX79-B18,133 Tags
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