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Nexperia USA Inc. BZX84W-B12-QX
- Part No.:
- BZX84W-B12-QX
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-70, SOT-323
- Datasheet:
-
BZX84W-B12-QX.pdf
- Description:
- DIODE ZENER 12V 275MW SOT323
- Quantity:
- Payment:
- Shipping:
Inventory:7,562
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Product details
Overview
BZX84W-B12-QX from Nexperia is a ±2% tolerance Zener voltage regulator diode in SOT323 (SC-70) package, rated for 12 V nominal Zener voltage at 5 mA, 275 mW total power dissipation, and qualified to AEC-Q101 for automotive use. It provides stable reference voltage in low-power regulation circuits such as ECU sensor biasing, CAN transceiver clamping, and microcontroller reset circuitry.
For engineers reviewing the BZX84W-B12-QX datasheet, BZX84W-B12-QX pinout, BZX84W-B12-QX application, or BZX84W-B12-QX equivalent, this page delivers verified Zener parameters, automotive-grade thermal and electrical specs, SOT323 terminal mapping, and validated alternatives for precision voltage reference design.
Technical Context
This Zener diode operates in reverse breakdown with a nominal 12.0 V Zener voltage (VZ) at IZ = 5 mA, differential resistance of 150 Ω max, and temperature coefficient of +8.4 mV/K - indicating positive drift with junction temperature rise. Its low 2.5 pF capacitance at 1 MHz enables use in high-frequency noise suppression.
It sustains non-repetitive peak reverse power up to 40 W for 100 µs pulses and maintains operation across −55 °C to +150 °C ambient range. The device is mounted on FR4 PCB with single-sided copper and standard SOT323 footprint per JEDEC MO-203AA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 11.8 V to 12.2 V at IZ = 5 mA - ensures tight 12 V reference under typical bias conditions |
| Tolerance | ±2 % - supports precision regulation without post-calibration in automotive sensor interfaces |
| Power Dissipation (Ptot) | 275 mW at Tamb = 25 °C on FR4 PCB - defines maximum continuous DC power handling in standard layout |
| Differential Resistance (rdif) | ≤150 Ω at IZ = 5 mA - determines output impedance and load regulation sensitivity |
| Reverse Current (IR) | ≤100 nA at VR = 8 V - guarantees low leakage in high-impedance reference nodes |
| Capacitance (Cd) | 2.5 pF at f = 1 MHz, VR = 0 V - enables effective RF bypass without signal distortion |
| Thermal Resistance (Rth(j-a)) | 455 K/W - sets junction-to-ambient temperature rise per watt in free-air mounting |
Pinout & Package
SOT323 (SC-70) plastic surface-mounted package with 3 leads; leadless construction optimized for automated reflow assembly and space-constrained PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode (A) | Forward-biased terminal; connects to lower-potential side in Zener regulation configuration |
| 2 | Not Connected (n.c.) | Internally unconnected; must remain floating - no PCB trace or solder mask required |
| 3 | Cathode (K) | Reverse-biased terminal; connects to higher-potential side and carries regulated output current |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive underhood and cabin applications including engine control, ADAS sensors, and infotainment power rails |
| Low dynamic impedance | 150 Ω max at 5 mA enables stable regulation under varying load currents in feedback loops |
| High-temperature operation | Junction temperature rating up to 150 °C supports deployment in thermally aggressive environments |
| Low capacitance | 2.5 pF allows integration into high-speed signal paths without degrading edge integrity or causing ringing |
| Standard SOT323 footprint | Compatible with industry-standard reflow profiles and wave-soldering footprints per Nexperia Fig. 9–10 |
Applications
| Automotive ECU Reference | CAN Bus Transceiver Clamping |
|---|---|
Use Scenario: Providing stable 12 V reference for analog-to-digital conversion in engine control unit (ECU) sensor signal conditioning. IC Role / Device Role / Timing Role: Zener voltage reference diode establishing precise bias point for op-amp input stages and ADC reference dividers. Use Value: ±2 % tolerance and +8.4 mV/K temperature coefficient enable <1 % total error over −40 °C to +125 °C operating range without trimming. |
Use Scenario: Protecting CANH/CANL lines from transient overvoltage events in vehicle networking systems. IC Role / Device Role / Timing Role: Bidirectional transient voltage suppressor configured as back-to-back Zener clamp between differential bus lines. Use Value: 40 W non-repetitive peak power rating absorbs ISO 7637-2 pulse 1/2a surges while maintaining <12.2 V clamping threshold. |
| Microcontroller Reset Circuit | Industrial Sensor Biasing |
Use Scenario: Generating clean, temperature-stable reset threshold for 3.3 V or 5 V microcontrollers in telematics modules. IC Role / Device Role / Timing Role: Zener-based voltage monitor feeding comparator input to trigger POR or brown-out detection. Use Value: 100 nA reverse leakage at 8 V ensures minimal current draw in battery-backed standby mode. |
Use Scenario: Supplying calibrated excitation voltage to resistive temperature detectors (RTDs) and strain gauges in factory automation equipment. IC Role / Device Role / Timing Role: Precision shunt regulator delivering constant 12 V bias independent of supply rail fluctuations. Use Value: 150 Ω differential resistance limits output voltage shift to ≤0.75 V across 5 mA load variation, ensuring measurement linearity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ON Semiconductor MMBZ5242B | 12 V, ±5 % tolerance, 350 mW Ptot, SOT-23 package | Higher power but looser tolerance; requires larger PCB area and lacks AEC-Q101 qualification | Select when cost sensitivity outweighs automotive compliance and precision requirements |
| Vishay BZX84-C12 | 12 V, ±5 % tolerance, 250 mW Ptot, same SOT323 package | Same footprint but wider tolerance and lower power rating; not AEC-Q101 qualified | Acceptable for industrial non-automotive designs where ±5 % regulation is sufficient |
Compared with MMBZ5242B and BZX84-C12, the BZX84W-B12-QX offers tighter ±2 % tolerance, AEC-Q101 qualification, and guaranteed 275 mW dissipation - making it the only choice for automotive-grade 12 V reference where long-term stability and regulatory compliance are mandatory.
Availability
BZX84W-B12-QX is available at Aetrix Electronics and suitable for automotive ECU design, CAN bus protection, and industrial sensor biasing requiring stable component supply, full traceability, and lifecycle continuity.
Supply support for BZX84W-B12-QX 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 essential efficiency technologies, delivering high-performance, reliable discrete and logic devices for automotive, industrial, and consumer markets.
The BZX84W-Q series belongs to Nexperia's automotive-qualified Zener diode product line, engineered specifically for precision voltage regulation and transient protection in harsh-environment electronic control units.
FAQ
What is the maximum continuous reverse current the BZX84W-B12-QX can sustain at 12 V?
The BZX84W-B12-QX is rated for 275 mW total power dissipation at 25 °C ambient on FR4 PCB. At its nominal 12 V Zener voltage, this corresponds to a maximum continuous reverse current of 22.9 mA (275 mW ÷ 12 V). Exceeding this current risks thermal runaway unless board-level heatsinking or derating is applied.
Is pin 2 electrically functional or should it be left unconnected?
Pin 2 is explicitly designated "n.c." (not connected) in Nexperia's official pinning information. It is internally isolated and must remain unconnected on the PCB - no trace, pad, or solder mask coverage is required or recommended. Connecting it may compromise reliability or cause unintended parasitic coupling.
How does the +8.4 mV/K temperature coefficient affect regulation accuracy over temperature?
With a +8.4 mV/K coefficient, the Zener voltage increases by approximately 0.84 V over a 100 K rise (e.g., −40 °C to +60 °C). For a 12 V nominal device, this yields ~7 % drift across that range. In practice, combined with ±2 % initial tolerance, total error remains within ±9 % - acceptable for non-critical biasing but insufficient for metrology-grade references without compensation.
Can the BZX84W-B12-QX replace the older BZX84-C12 in existing designs?
Yes, mechanically and electrically - both use SOT323 and regulate near 12 V - but the BZX84W-B12-QX offers ±2 % tolerance versus ±5 %, AEC-Q101 qualification, and 275 mW vs. 250 mW power rating. Replacement improves accuracy and automotive compliance but requires validation of thermal margin due to higher power capability.
BZX84W-B12-QX 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):
- 12 V
- Tolerance:
- ±1.67%
- Power - Max:
- 275 mW
- Impedance (Max) (Zzt):
- 25 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 8 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-B12-QX FAQ
1.How can I place an order for BZX84W-B12-QX through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84W-B12-QX 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-B12-QX reliable?
The price and inventory of BZX84W-B12-QX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX84W-B12-QX is usually 5 days.
3.What payment methods are accepted for BZX84W-B12-QX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84W-B12-QX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84W-B12-QX?
BZX84W-B12-QX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84W-B12-QX 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-B12-QX?
For technical support, including BZX84W-B12-QX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84W-B12-QX requirements.
6.How does Aetrix verify that BZX84W-B12-QX is sourced from the original manufacturer or authorized distributors?
All BZX84W-B12-QX 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-B12-QX meets industry standards.
7.What is the process for return or replacement of BZX84W-B12-QX?
All BZX84W-B12-QX units undergo pre-shipment inspection (PSI). If there is an issue with BZX84W-B12-QX, 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-B12-QX part is unused and in its original packaging.
Return procedure for BZX84W-B12-QX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84W-B12-QX Tags
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