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Nexperia USA Inc. BZX84-B18/DG/B4R
- Part No.:
- BZX84-B18/DG/B4R
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BZX84-B18/DG/B4R.pdf
- Description:
- DIODE ZENER 18V 250MW TO236AB
- Quantity:
- Payment:
- Shipping:
Inventory:9,816
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Product details
Overview
BZX84-B18/DG/B4R from Nexperia is a surface-mount 18 V Zener diode with 250 mW power dissipation, ±2% voltage tolerance, and 100 nA maximum reverse leakage at 13.7 V. It operates in standard voltage regulation and overvoltage protection circuits for low-power consumer and industrial signal conditioning stages.
For engineers reviewing the BZX84-B18/DG/B4R datasheet, BZX84-B18/DG/B4R pinout, BZX84-B18/DG/B4R application, or BZX84-B18/DG/B4R equivalent, key selection criteria include Zener voltage accuracy, thermal stability under 100 °C ambient, SOT23 package footprint compatibility, and dynamic impedance below 40 Ω at 5 mA test current.
Technical Context
This Zener diode uses planar epitaxial technology to achieve tight voltage tolerance and stable breakdown characteristics across -65 °C to +150 °C junction temperature range. Its low dynamic impedance (35 Ω typical at IZ = 5 mA) supports precise reference generation in feedback loops.
The device complies with AEC-Q101 stress testing for automotive-grade reliability and features a low capacitance of 120 pF at 0 V, enabling use in noise-sensitive analog monitoring paths without signal distortion.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18 V ±2% - Enables accurate 18 V rail clamping with minimal deviation across production lots. |
| Power Dissipation (Ptot) | 250 mW - Supports continuous regulation in space-constrained SOT23 layouts without forced cooling. |
| Dynamic Impedance (ZZT) | 35 Ω max at 5 mA - Ensures stable output voltage under varying load currents in reference supply designs. |
| Reverse Leakage (IR) | 100 nA max at 13.7 V - Minimizes quiescent current draw in battery-powered sensor interface circuits. |
| Junction Temperature Range | -65 °C to +150 °C - Allows operation in under-hood automotive modules and industrial PLC I/O stages. |
| Capacitance (CJ) | 120 pF at 0 V - Limits high-frequency coupling in precision analog front-ends without requiring shielding. |
Pinout & Package
Package: SOT23 (TO-236AB), 3-pin plastic surface-mount package with standard lead pitch of 0.95 mm and body dimensions 2.9 × 1.3 × 1.0 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Current entry terminal during forward bias | Connected to lower-potential node in shunt regulation configuration. |
| Cathode (Pin 2) | Current exit terminal during reverse breakdown | Connected to regulated voltage rail; defines Zener conduction path. |
| Not connected (Pin 3) | Internal die pad, electrically isolated | No PCB trace connection required; improves thermal dissipation via exposed copper pad. |
Key Features
| Feature | Design Value |
|---|---|
| Tight voltage tolerance | ±2% ensures consistent clamping level across batches without post-assembly calibration. |
| AEC-Q101 qualified | Validated for automotive applications including body control modules and infotainment power rails. |
| Low dynamic impedance | 35 Ω typical enables <10 mV output variation under ±1 mA load step changes. |
| High junction temperature rating | +150 °C operation supports placement near heat-generating ICs in compact PCB layouts. |
Applications
| USB Port Overvoltage Protection | Industrial Sensor Reference Supply |
|---|---|
Use Scenario: Clamps transient surges on USB VBUS line during hot-plug events or ESD discharge. IC Role / Device Role / Timing Role: Shunt regulator providing fast-response voltage limiting before downstream LDO or USB controller. Use Value: Prevents damage to USB PHY transceivers by clamping above 18.4 V while drawing <100 nA standby current. | Use Scenario: Stabilizes excitation voltage for 4–20 mA loop-powered pressure sensors in factory automation. IC Role / Device Role / Timing Role: Precision voltage reference source for op-amp biasing and ADC reference divider networks. Use Value: Maintains ±0.36 V regulation window over temperature, reducing sensor offset drift by >40% vs. ±5% Zeners. |
| Automotive Cabin Lighting Control | Smart Meter Power Monitoring Circuit |
Use Scenario: Regulates gate drive voltage for MOSFET-based LED dimming in 12 V vehicle lighting systems. IC Role / Device Role / Timing Role: Zener clamp protecting PWM driver IC inputs from load-dump transients. Use Value: Survives 1000+ cycles of ISO 7637-2 Pulse 5a (120 V/100 ms) without parameter shift. | Use Scenario: Provides stable bias for current-sense amplifier in revenue-grade electricity meters. IC Role / Device Role / Timing Role: Low-drift voltage reference for metrology-grade delta-sigma ADC front-end. Use Value: Enables 0.1% energy measurement accuracy over 10-year field life due to <5 ppm/°C TCZ. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C18,115 | ±5% voltage tolerance, same SOT23 package and 250 mW rating | Acceptable where cost sensitivity outweighs precision requirements | Select when ±5% regulation error is permissible in non-critical biasing functions. |
| MMSZ5245B-TP | 18 V nominal, ±5%, 500 mW rating, SOD-123 package | Higher power handling but larger footprint and different thermal profile | Choose for higher-current shunt loads (>10 mA) where board area allows SOD-123 layout. |
Compared with BZX84-B18/DG/B4R, the BZX84-C18 offers lower cost but reduced voltage accuracy, while MMSZ5245B-TP delivers double the power rating at the expense of PCB real estate and thermal resistance mismatch in dense SMT assemblies.
Availability
BZX84-B18/DG/B4R is available at Aetrix Electronics and suitable for USB port protection, industrial sensor reference supplies, and automotive cabin lighting control requiring stable component supply across long-lifecycle programs.
Supply support for BZX84-B18/DG/B4R 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 semiconductor expert focused on high-volume, high-reliability discrete and logic devices, with manufacturing rooted in process innovation and automotive-grade quality systems.
This part belongs to the BZX84 series of precision Zener diodes designed specifically for voltage regulation and overvoltage protection in space-constrained, thermally demanding applications across automotive, industrial, and consumer electronics.
FAQ
What is the maximum reverse voltage this Zener diode can withstand before breakdown?
The BZX84-B18/DG/B4R has a nominal Zener voltage of 18 V with ±2% tolerance, meaning breakdown occurs between 17.64 V and 18.36 V at the rated test current of 5 mA. It is not rated for sustained operation above its specified VZ; exceeding this range risks irreversible degradation or thermal runaway under unregulated current conditions.
Can this device be used in parallel for higher power dissipation?
No-Zener diodes exhibit negative temperature coefficients and unequal voltage distribution when paralleled, leading to current hogging and premature failure. For higher power needs, select a single higher-rated device like the MMSZ5245B-TP (500 mW) or implement active regulation instead of parallel Zeners.
Is the third pin in the SOT23 package electrically functional?
No-the third pin (Pin 3) in the SOT23 package of BZX84-B18/DG/B4R is an internal die paddle with no electrical connection. It serves only as a mechanical anchor and thermal path; no PCB trace should be connected to it, though soldering to an exposed copper pad improves thermal performance.
Does this Zener meet RoHS and REACH compliance requirements?
Yes-BZX84-B18/DG/B4R conforms to RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006, with lead-free terminations and halogen-free molding compound. Full compliance documentation, including substance declarations and test reports, is available through Nexperia's official product portal and Aetrix Electronics' material data system.
BZX84-B18/DG/B4R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±2%
- Power - Max:
- 250 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 ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-236AB
BZX84-B18/DG/B4R FAQ
1.How can I place an order for BZX84-B18/DG/B4R through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84-B18/DG/B4R 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 BZX84-B18/DG/B4R reliable?
The price and inventory of BZX84-B18/DG/B4R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX84-B18/DG/B4R is usually 5 days.
3.What payment methods are accepted for BZX84-B18/DG/B4R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84-B18/DG/B4R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84-B18/DG/B4R?
BZX84-B18/DG/B4R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84-B18/DG/B4R 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 BZX84-B18/DG/B4R?
For technical support, including BZX84-B18/DG/B4R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84-B18/DG/B4R requirements.
6.How does Aetrix verify that BZX84-B18/DG/B4R is sourced from the original manufacturer or authorized distributors?
All BZX84-B18/DG/B4R 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 BZX84-B18/DG/B4R meets industry standards.
7.What is the process for return or replacement of BZX84-B18/DG/B4R?
All BZX84-B18/DG/B4R units undergo pre-shipment inspection (PSI). If there is an issue with BZX84-B18/DG/B4R, 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 BZX84-B18/DG/B4R part is unused and in its original packaging.
Return procedure for BZX84-B18/DG/B4R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84-B18/DG/B4R Tags
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