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Nexperia USA Inc. BZX84W-B4V3-QX
- Part No.:
- BZX84W-B4V3-QX
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-70, SOT-323
- Datasheet:
-
BZX84W-B4V3-QX.pdf
- Description:
- DIODE ZENER 4.3V 275MW SOT323
- Quantity:
- Payment:
- Shipping:
Inventory:2,572
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Product details
Overview
BZX84W-B4V3-QX from Nexperia is a ±2 % tolerance Zener voltage regulator diode in SOT323 (SC-70) package, rated for 4.3 V nominal Zener voltage at 5 mA, 275 mW total power dissipation, and qualified to AEC-Q101 for automotive use. It provides precise voltage reference and overvoltage protection in compact power management circuits such as ECU voltage supervisors and sensor biasing networks.
For engineers reviewing the BZX84W-B4V3-QX datasheet, BZX84W-B4V3-QX pinout, BZX84W-B4V3-QX application, or BZX84W-B4V3-QX equivalent, this page delivers verified Zener parameters, automotive-grade thermal limits, SC-70 terminal mapping, and validated alternatives for voltage regulation in space-constrained, high-reliability designs.
Technical Context
This Zener diode operates in reverse breakdown mode with a typical differential resistance of 90 Ω at 5 mA and a temperature coefficient of −2.5 mV/K, enabling stable regulation across ambient temperatures from −55 °C to +150 °C. Its non-repetitive peak reverse power dissipation reaches 40 W for 100 µs pulses, supporting transient suppression in automotive load-dump scenarios.
The device features low reverse leakage-3 µA maximum at VR = 1 V-and forward voltage ≤0.9 V at IF = 10 mA. Its junction-to-ambient thermal resistance is 455 K/W on standard FR4 PCB, defining safe continuous power derating above 25 °C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 4.21 V to 4.39 V at IZ = 5 mA; ensures tight 4.3 V regulation for precision reference circuits |
| Tolerance | ±2 % (B-series); guarantees voltage accuracy within ±0.086 V for critical biasing applications |
| Power Dissipation (Ptot) | 275 mW at Tamb = 25 °C on FR4 PCB; defines maximum steady-state power handling in standard layout |
| Differential Resistance (rdif) | 90 Ω max at IZ = 5 mA; determines output impedance and regulation sensitivity to current variation |
| Reverse Leakage (IR) | 3 µA max at VR = 1 V; minimizes quiescent current loss in low-power standby circuits |
| Junction Temperature (Tj) | 150 °C max; sets upper thermal limit for operation in under-hood automotive environments |
| AEC-Q101 Qualified | Yes; confirms reliability for automotive electronics including engine control and ADAS modules |
Pinout & Package
Package: SOT323 (SC-70), leadless surface-mount plastic package with 3 terminals, footprint dimensions per Figure 9 (reflow) and Figure 10 (wave soldering) in datasheet Rev. 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode (A) | Forward-biased terminal; connects to lower-potential node in regulation path |
| 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 regulated voltage rail and current-limiting resistor |
Key Features
| Feature | Design Value |
|---|---|
| Automotive qualification | AEC-Q101 compliant-validated for vibration, temperature cycling, and humidity resistance in vehicle ECUs |
| Low-leakage Zener operation | 3 µA max reverse current at 1 V enables ultra-low-power voltage monitoring in battery-backed systems |
| Precision voltage tolerance | ±2 % (B-series) supports accurate 4.3 V reference without external trimming in sensor signal chains |
| High pulse power capability | 40 W non-repetitive peak reverse power at 100 µs enables transient clamping in CAN/LIN bus protection |
| Thermal robustness | 150 °C max junction temperature allows operation near heat-generating components in power modules |
Applications
| Engine Control Unit (ECU) Voltage Supervisor | Automotive Sensor Biasing |
|---|---|
|
Use Scenario: Monitoring 5 V supply rail in engine control module to detect undervoltage/overvoltage faults. IC Role / Device Role / Timing Role: Zener diode acts as precision shunt reference for comparator input, triggering fault flag when rail deviates beyond ±5 %. Use Value: ±2 % tolerance ensures detection threshold remains within 4.21–4.39 V, minimizing false alarms during cold cranking transients. |
Use Scenario: Providing stable 4.3 V bias to analog output sensors (e.g., pressure, temperature) in ADAS camera modules. IC Role / Device Role / Timing Role: Functions as low-noise, low-drift voltage reference for sensor excitation circuitry. Use Value: −2.5 mV/K temperature coefficient maintains <±10 mV drift over −40 °C to +125 °C operating range. |
| Infotainment System Power Sequencing | Body Control Module (BCM) Overvoltage Clamp |
|
Use Scenario: Enabling controlled power-up sequence for multi-rail infotainment SoCs by holding reset line until 4.3 V rail stabilizes. IC Role / Device Role / Timing Role: Zener diode forms part of RC-delayed reset generator, asserting reset until regulated voltage exceeds threshold. Use Value: 90 Ω differential resistance ensures minimal voltage droop during reset assertion, preserving timing margin. |
Use Scenario: Clamping 12 V battery line against load-dump spikes (>40 V) in door module power inputs. IC Role / Device Role / Timing Role: Shunt protector activated during transient events, diverting surge current away from downstream LDOs. Use Value: 40 W non-repetitive peak power rating absorbs 100 µs surges without degradation, meeting ISO 7637-2 Pulse 5a requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84W-C4V3-Q | ±5 % tolerance (4.00–4.60 V), higher reverse leakage (3 µA same, but wider distribution) | Suitable for non-critical biasing where cost outweighs precision | Select when ±5 % regulation suffices and AEC-Q101 compliance is retained |
| MMSZ4V3T1G | ±5 % tolerance, SOD-123 package, 500 mW Ptot, not AEC-Q101 qualified | Higher power handling but lacks automotive qualification and tighter tolerance | Use only in industrial or consumer applications requiring >275 mW dissipation |
Compared with BZX84W-B4V3-QX, the C4V3-Q offers relaxed tolerance at identical qualification, while MMSZ4V3T1G trades automotive reliability for higher power and larger footprint-neither matches the original's combination of ±2 % accuracy, AEC-Q101, and SOT323 size.
Availability
BZX84W-B4V3-QX is available at Aetrix Electronics and suitable for automotive ECU voltage supervision, ADAS sensor biasing, and BCM overvoltage clamping requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for BZX84W-B4V3-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 high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified components and energy-efficient solutions.
The BZX84W-Q series belongs to Nexperia's automotive Zener diode product line, engineered specifically for precision voltage regulation and transient protection in harsh-environment vehicle subsystems.
FAQ
What is the maximum continuous forward current for BZX84W-B4V3-QX?
The absolute maximum forward current is 200 mA per Table 5 (Limiting Values). However, sustained forward conduction is not intended-this Zener is designed for reverse-bias regulation. Forward voltage is specified at 10 mA (≤0.9 V), and operation above 100 mA risks thermal runaway due to its 275 mW power limit and 455 K/W thermal resistance.
Can BZX84W-B4V3-QX replace a 4.3 V Zener with ±5 % tolerance in an automotive design?
Yes-it meets or exceeds all electrical and qualification requirements of ±5 % parts (e.g., BZX84W-C4V3-Q), with tighter voltage control (±2 %), identical AEC-Q101 qualification, and same SOT323 package. No layout or schematic changes are needed, and the improved tolerance enhances system-level accuracy in voltage monitoring functions.
How does the n.c. pin (Pin 2) affect PCB layout?
Pin 2 is internally unconnected and must remain electrically isolated-no copper trace, solder mask opening, or thermal pad should contact it. The SOT323 footprint in Figure 9 specifies 0.5 mm pad width and 0.55 mm spacing; violating this risks shorting to adjacent pins or compromising mechanical stability during reflow.
What is the recommended minimum current to maintain stable Zener regulation?
Stable regulation begins at IZ ≥ 1 mA, where reverse leakage is guaranteed ≤3 µA and voltage remains within spec. For full accuracy, operate at 5 mA-the condition used for VZ, rdif, and temperature coefficient specifications. Below 0.5 mA, voltage deviation increases significantly, especially near knee region.
BZX84W-B4V3-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):
- 4.3 V
- Tolerance:
- ±2.09%
- Power - Max:
- 275 mW
- Impedance (Max) (Zzt):
- 90 Ohms
- Current - Reverse Leakage @ Vr:
- 3 µA @ 1 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-B4V3-QX FAQ
1.How can I place an order for BZX84W-B4V3-QX through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84W-B4V3-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-B4V3-QX reliable?
The price and inventory of BZX84W-B4V3-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-B4V3-QX is usually 5 days.
3.What payment methods are accepted for BZX84W-B4V3-QX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84W-B4V3-QX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84W-B4V3-QX?
BZX84W-B4V3-QX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84W-B4V3-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-B4V3-QX?
For technical support, including BZX84W-B4V3-QX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84W-B4V3-QX requirements.
6.How does Aetrix verify that BZX84W-B4V3-QX is sourced from the original manufacturer or authorized distributors?
All BZX84W-B4V3-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-B4V3-QX meets industry standards.
7.What is the process for return or replacement of BZX84W-B4V3-QX?
All BZX84W-B4V3-QX units undergo pre-shipment inspection (PSI). If there is an issue with BZX84W-B4V3-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-B4V3-QX part is unused and in its original packaging.
Return procedure for BZX84W-B4V3-QX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84W-B4V3-QX Tags
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
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BZX84C3V3LT1G
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MMSZ5245BS-7-F
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MMSZ4682T1G
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BZT52C15S-7-F
Diodes Incorporated
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MM5Z5V1ST1G
onsemi
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