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Nexperia USA Inc. BZX84W-B18-QF
- Part No.:
- BZX84W-B18-QF
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-70, SOT-323
- Datasheet:
-
BZX84W-B18-QF.pdf
- Description:
- DIODE ZENER 18V 275MW SOT323
- Quantity:
- Payment:
- Shipping:
Inventory:8,469
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Product details
Overview
BZX84W-B18-QF from Nexperia is a ±2 % tolerance Zener voltage regulator diode with a nominal 18 V breakdown voltage, 225 Ω differential resistance at 5 mA, and 14.4 mV/K temperature coefficient, housed in an AEC-Q101-qualified SOT323 (SC-70) package for automotive power rail stabilization.
For engineers reviewing the BZX84W-B18-QF datasheet, BZX84W-B18-QF pinout, BZX84W-B18-QF application, or BZX84W-B18-QF equivalent, this device serves as a precision shunt reference in low-power voltage regulation, ESD-protected bias networks, and high-frequency feedback loops where thermal stability and compact footprint are critical.
Technical Context
This Zener diode operates in reverse-bias breakdown mode to maintain a stable 18 V reference across its cathode-anode terminals under regulated current conditions. Its ±2 % tolerance and 14.4 mV/K temperature coefficient enable predictable drift behavior over −55 °C to +150 °C ambient range.
The device delivers 275 mW total power dissipation on FR4 PCB with single-sided copper, supports non-repetitive 40 W surge pulses (tp = 100 µs), and exhibits 1.5 pF junction capacitance at 1 MHz and 0 V reverse bias-enabling use in noise-sensitive analog and RF-coupled circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 17.6 V to 18.4 V at IZ = 5 mA - tight ±2 % tolerance ensures accurate voltage clamping in safety-critical automotive subsystems. |
| Differential Resistance (rdif) | 225 Ω max at IZ = 5 mA - low dynamic impedance maintains regulation stability under varying load currents. |
| Temperature Coefficient (SZ) | +14.4 mV/K at IZ = 5 mA - positive drift enables predictable compensation in temperature-varying environments. |
| Reverse Current (IR) | 50 nA max at VR = 12.6 V - ultra-low leakage preserves battery life in always-on vehicle modules. |
| Total Power Dissipation (Ptot) | 275 mW at Tamb = 25 °C on standard FR4 - sufficient headroom for continuous operation in engine control unit (ECU) sensor interfaces. |
| Junction-to-Ambient Thermal Resistance (Rth(j-a)) | 455 K/W - defines thermal derating slope for reliable operation up to +150 °C junction temperature. |
| Package | SOT323 (SC-70) - 1.3 mm × 1.8 mm footprint enables high-density placement on space-constrained automotive PCBs. |
Pinout & Package
SOT323 (SC-70) leadless surface-mount package with 3 terminals: anode (Pin 1), not connected (Pin 2), cathode (Pin 3). The n.c. terminal provides mechanical symmetry and thermal relief without electrical function.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode | Forward-current entry point; connects to lower-potential node in shunt regulation configuration. |
| 2 | Not Connected | Electrically isolated terminal; used for mechanical balance and thermal dissipation path only. |
| 3 | Cathode | Reverse-bias voltage reference node; ties to regulated rail or feedback divider in voltage reference circuits. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive-grade reliability including temperature cycling, humidity testing, and mechanical shock per JESD22 standards. |
| ±2 % Zener voltage tolerance | Reduces need for post-production trimming in ADAS sensor supply rails and infotainment voltage references. |
| 1.5 pF junction capacitance | Minimizes signal distortion in high-frequency feedback paths of DC-DC converters operating above 10 MHz. |
| 40 W non-repetitive surge rating | Withstands transient overvoltage events such as load dump (ISO 7637-2 Pulse 5a) without degradation. |
| −55 °C to +150 °C operating range | Supports under-hood deployment in engine management systems without external thermal buffering. |
Applications
| Automotive Engine Control Unit (ECU) Reference | Infotainment System Power Sequencing |
|---|---|
|
Use Scenario: Providing stable 18 V reference for microcontroller reset circuitry and analog sensor front-ends in gasoline/diesel ECUs. IC Role / Device Role / Timing Role: Shunt voltage reference regulating bias voltage for ADC reference buffers and watchdog timer comparators. Use Value: ±2 % tolerance and +14.4 mV/K coefficient ensure reset threshold remains within 18.2 V ±0.15 V across −40 °C to +125 °C engine bay temperatures. |
Use Scenario: Clamping auxiliary 18 V rail during cold-cranking transients in head-unit power management. IC Role / Device Role / Timing Role: Overvoltage protection element absorbing ISO 7637-2 Pulse 5a energy spikes before reaching PMIC inputs. Use Value: 40 W non-repetitive surge rating and 275 mW steady-state dissipation prevent latch-up during 12 V system dips to 6 V and rebounds to 16 V. |
| ADAS Camera Module Bias Network | Body Control Module (BCM) CAN Transceiver Reference |
|
Use Scenario: Generating precise bias voltage for CMOS image sensor analog front-end stages in surround-view cameras. IC Role / Device Role / Timing Role: Low-noise Zener reference source feeding op-amp gain-setting resistors and pixel ADC reference ladders. Use Value: 1.5 pF capacitance and 225 Ω rdif suppress switching noise coupling from nearby 2 MHz clock traces into analog video signal chain. |
Use Scenario: Stabilizing 18 V supply to isolated CAN FD transceiver bias rails in door module communication nodes. IC Role / Device Role / Timing Role: Local shunt regulator maintaining clean VCC for CAN driver stage during LIN bus wake-up transitions. Use Value: 50 nA leakage at 12.6 V reverse bias prevents parasitic current draw that would delay sleep-mode entry in always-on BCM domains. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84W-C18-Q | ±5 % tolerance (16.8 V–19.1 V), higher 250 Ω rdif, identical package and surge rating | Acceptable where cost sensitivity outweighs precision; less suitable for ADC reference or reset threshold circuits | Select when design tolerates wider output variation and requires lower BOM cost in non-safety-critical lighting modules. |
| MMSZ5245B-TP | ±5 % tolerance (17.1 V–18.9 V), 200 Ω rdif, SOD-123 package (larger footprint, higher Rth(j-a) = 500 K/W) | Compatible for board-level replacement but lacks AEC-Q101 qualification and automotive traceability | Use only in industrial or consumer designs where automotive qualification and thermal performance are not required. |
Compared with BZX84W-C18-Q and MMSZ5245B-TP, the BZX84W-B18-QF offers superior voltage accuracy and automotive qualification-critical for ECU reset logic and ADAS sensor biasing-while its SOT323 footprint enables higher PCB density than SOD-123 alternatives.
Availability
BZX84W-B18-QF is available at Aetrix Electronics and suitable for automotive engine control units, ADAS camera modules, infotainment power sequencing, and body control module CAN transceiver references requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for BZX84W-B18-QF 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 leadership in automotive-qualified components and advanced packaging technologies.
The BZX84W-Q series belongs to Nexperia's AEC-Q101-certified Zener diode product line, engineered specifically for precision voltage regulation and transient suppression in harsh automotive environments.
FAQ
What is the maximum continuous reverse current the BZX84W-B18-QF can sustain without degradation?
The device supports a maximum forward current of 200 mA per Absolute Maximum Ratings, but as a Zener diode, it operates in reverse breakdown. At its rated 18 V Zener voltage and 275 mW power dissipation limit, the maximum continuous reverse current is 15.3 mA (275 mW ÷ 18 V). Exceeding this value risks thermal runaway unless heatsinking or derating is applied per Rth(j-a) = 455 K/W.
How does the "QF" suffix in BZX84W-B18-QF differ from standard BZX84W-B18-Q?
The "QF" suffix denotes Nexperia's automotive-grade variant with full AEC-Q101 qualification, including enhanced traceability, lot-level test data reporting, and extended temperature screening (−55 °C to +150 °C). Standard "Q" parts meet commercial specifications and lack the automotive audit trail, material composition documentation, and stress-test validation required for Tier 1 automotive supply chains.
Can BZX84W-B18-QF replace BZX84C18 in existing designs?
Yes, with caveats: both share identical SOT323 package and 18 V nominal voltage, but BZX84W-B18-QF has ±2 % tolerance (17.6–18.4 V) versus BZX84C18's ±5 % (17.1–18.9 V), lower rdif (225 Ω vs. 250 Ω), and AEC-Q101 qualification. Replacement is safe if the design benefits from tighter regulation and automotive compliance-but verify thermal margin, as power dissipation limits are identical.
Why does Pin 2 show "n.c." and how should it be handled on the PCB?
Pin 2 is electrically not connected and serves only mechanical and thermal functions: it improves solder joint reliability during reflow and provides additional copper area for heat spreading. On the PCB, it must be routed as a standalone pad-neither tied to ground nor left floating in copper pour. The recommended footprint (Fig. 9) specifies a 0.55 mm × 0.55 mm isolated pad with 0.5 mm solder mask opening to ensure consistent wetting and avoid tombstoning.
BZX84W-B18-QF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- BZX84W-Q
- Package/Case:
- SC-70, SOT-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±2.22%
- Power - Max:
- 275 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:
- 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-323
BZX84W-B18-QF FAQ
1.How can I place an order for BZX84W-B18-QF through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84W-B18-QF 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 BZX84W-B18-QF reliable?
The price and inventory of BZX84W-B18-QF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX84W-B18-QF is usually 5 days.
3.What payment methods are accepted for BZX84W-B18-QF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84W-B18-QF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84W-B18-QF?
BZX84W-B18-QF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84W-B18-QF 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 BZX84W-B18-QF?
For technical support, including BZX84W-B18-QF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84W-B18-QF requirements.
6.How does Aetrix verify that BZX84W-B18-QF is sourced from the original manufacturer or authorized distributors?
All BZX84W-B18-QF 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 BZX84W-B18-QF meets industry standards.
7.What is the process for return or replacement of BZX84W-B18-QF?
All BZX84W-B18-QF units undergo pre-shipment inspection (PSI). If there is an issue with BZX84W-B18-QF, 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 BZX84W-B18-QF part is unused and in its original packaging.
Return procedure for BZX84W-B18-QF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84W-B18-QF Tags
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MMBZ5240B-7-F
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
Diodes Incorporated
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BZT52C15-7-F
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BZX84C3V3LT1G
onsemi
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MMSZ5245BS-7-F
Diodes Incorporated
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MMSZ4682T1G
onsemi
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BZT52C15S-7-F
Diodes Incorporated
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MM5Z5V1ST1G
onsemi
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SMAJ4744A-TP
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BZT52C3V6LP-7
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SMAZ12-13-F
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