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Nexperia USA Inc. BZX84W-B39-QF
- Part No.:
- BZX84W-B39-QF
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-70, SOT-323
- Datasheet:
-
BZX84W-B39-QF.pdf
- Description:
- DIODE ZENER 39V 275MW SOT323
- Quantity:
- Payment:
- Shipping:
Inventory:8,638
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Product details
Overview
BZX84W-B39-QF from Nexperia is a ±2% tolerance Zener voltage regulator diode in SOT323 (SC-70) package, rated for 39 V nominal regulation at 5 mA, with 350 Ω typical differential resistance and 36.4 mV/K temperature coefficient. It delivers 275 mW total power dissipation on FR4 PCB and supports automotive-grade operation per AEC-Q101.
For engineers reviewing the BZX84W-B39-QF datasheet, BZX84W-B39-QF pinout, BZX84W-B39-QF application, or BZX84W-B39-QF equivalent, this part is selected for precision low-power voltage reference, overvoltage clamping in sensor interfaces, and ESD-robust biasing in automotive control modules where tight Zener tolerance and thermal stability are critical.
Technical Context
This Zener diode operates in reverse breakdown to maintain stable 39 V output across load and line variations, with specified test current of 5 mA and maximum reverse current of 50 nA at 0.7 × VZnom. Its junction-to-ambient thermal resistance is 455 K/W under standard FR4 mounting conditions.
The device exhibits a positive temperature coefficient of +36.4 mV/K at IZ = 5 mA, indicating voltage increases with temperature - a key design consideration for high-temperature automotive environments. Non-repetitive peak reverse power capability reaches 40 W for 100 µs pulses.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 39 V at IZ = 5 mA - defines primary regulation point for feedback or reference circuits |
| Tolerance | ±2% (B-series) - enables tighter voltage margin control vs. ±5% C-series alternatives |
| Differential Resistance | 350 Ω max at IZ = 2 mA - determines output impedance and load regulation sensitivity |
| Temperature Coefficient | +36.4 mV/K at IZ = 2 mA - quantifies voltage drift per degree Celsius rise in junction temperature |
| Total Power Dissipation | 275 mW at Tamb = 25 °C on FR4 - sets maximum continuous DC power handling under standard layout |
| Reverse Current | 50 nA max at VR = 0.7 × VZnom - defines leakage level critical for low-power standby circuits |
| Package | SOT323 (SC-70) - ultra-small 3-lead surface-mount footprint compatible with high-density automotive PCBs |
Pinout & Package
SOT323 (SC-70) leadless plastic package with 3 terminals: anode (Pin 1), not-connected (Pin 2), cathode (Pin 3). Pin 2 is internally unconnected and must remain floating in circuit layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode | Forward-biased terminal; connected to lower potential side in Zener regulation configuration |
| 2 | Not Connected | No internal bond; must be left unconnected on PCB to avoid parasitic coupling or shorting |
| 3 | Cathode | Reverse-biased terminal; connected to higher potential side and serves as regulated output node |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive applications including engine control units and body electronics |
| ±2% Zener voltage tolerance | Reduces calibration overhead in precision reference designs versus ±5% variants |
| Low capacitance (0.7 pF) | Minimizes signal distortion in high-frequency clamp or RF bias applications |
| Non-repetitive surge rating | Withstands 40 W transient pulses (100 µs), supporting robust ESD/overvoltage protection |
Applications
| Automotive Sensor Biasing | Industrial Analog Input Protection |
|---|---|
Use Scenario: Providing stable 39 V bias to Hall-effect position sensors in transmission control modules. IC Role / Device Role / Timing Role: Zener voltage reference and overvoltage clamp protecting ADC front-end inputs. Use Value: Maintains sensor accuracy across −40 °C to +125 °C ambient while suppressing transients exceeding ISO 7637-2 Pulse 5a. |
Use Scenario: Clamping analog input lines of PLC analog I/O modules exposed to field wiring surges. IC Role / Device Role / Timing Role: Reverse-biased shunt regulator limiting input voltage to protect op-amp and ADC stages. Use Value: Limits fault voltage to ≤39.8 V (max VZ) with <350 Ω dynamic impedance, preventing damage during 1 kV/µs transients. |
| Low-Power Reference Supply | USB-C Port Overvoltage Clamp |
Use Scenario: Generating local 39 V reference for isolated gate drivers in 12 V automotive subsystems. IC Role / Device Role / Timing Role: Precision Zener reference source with minimal quiescent current draw. Use Value: Draws only 50 nA leakage at 27.3 V (0.7 × 39 V), enabling microamp-level standby operation. |
Use Scenario: Protecting USB-C CC logic pins from accidental 48 V PD negotiation faults. IC Role / Device Role / Timing Role: Fast-acting shunt clamp triggered when CC line exceeds safe threshold. Use Value: Responds within nanoseconds to clamp at 39.8 V (VZ max), well below USB-C 56 V absolute max rating. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84W-C39-Q | ±5% tolerance (37–41 V range) vs. ±2% (38.2–39.8 V) | Acceptable where system-level calibration compensates for wider voltage spread | Select for cost-sensitive non-critical biasing where tighter tolerance is unnecessary |
| MMSZ4702T1G | 39 V nominal, ±5%, SOD-123 package, 500 mW Ptot, higher Rdif (700 Ω) | Larger footprint and lower thermal performance; suited for non-automotive industrial use | Choose when board space allows larger package and higher power margin is required |
Compared with BZX84W-B39-QF, the BZX84W-C39-Q offers lower cost but sacrifices 2.5× voltage accuracy, while MMSZ4702T1G trades miniaturization and AEC-Q101 compliance for higher power headroom and relaxed thermal constraints.
Availability
BZX84W-B39-QF is available at Aetrix Electronics and suitable for automotive sensor biasing, industrial analog input protection, and low-power reference supply requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for BZX84W-B39-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.
The BZX84W-Q series targets automotive and industrial Zener regulation needs, delivering AEC-Q101-compliant voltage references in ultra-compact SOT323 packages for space-constrained, thermally demanding environments.
FAQ
What is the maximum continuous reverse current the BZX84W-B39-QF can sustain without degradation?
The device has no specified maximum continuous reverse current beyond its 5 mA test condition; sustained operation above 5 mA requires derating based on thermal limits. At 25 °C ambient on FR4, 275 mW power dissipation allows ~7 mA at 39 V before reaching thermal limit, but long-term reliability is optimized at or below 5 mA per datasheet characterization.
Can Pin 2 (n.c.) be grounded or tied to a signal trace?
No - Pin 2 is internally unconnected and must remain electrically floating. Connecting it to ground or any signal introduces risk of parasitic coupling, unintended current paths, or mechanical stress on the die bond. The datasheet explicitly defines it as "not connected" and shows no internal connection in the simplified outline.
How does the +36.4 mV/K temperature coefficient impact regulation accuracy over −40 °C to +125 °C?
Over that 165 K range, the Zener voltage shifts by approximately +6.0 V (36.4 mV/K × 165 K), resulting in a total regulation band of 39.0 V to 45.0 V. This drift must be accommodated in system-level tolerance budgets - e.g., using post-regulation filtering or digital calibration in closed-loop systems.
Is the 40 W non-repetitive peak power rating usable for repetitive 100 µs pulses at 1 kHz?
No - the 40 W rating applies only to single, non-repetitive pulses. For repetitive operation, average power must stay within 275 mW. At 1 kHz and 100 µs pulse width (10% duty cycle), maximum allowable peak power is 2.75 W (275 mW ÷ 0.1), far below 40 W. Thermal accumulation would otherwise exceed junction temperature limits.
BZX84W-B39-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):
- 39 V
- Tolerance:
- ±2.05%
- Power - Max:
- 275 mW
- Impedance (Max) (Zzt):
- 130 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 27.3 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-B39-QF FAQ
1.How can I place an order for BZX84W-B39-QF through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84W-B39-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-B39-QF reliable?
The price and inventory of BZX84W-B39-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-B39-QF is usually 5 days.
3.What payment methods are accepted for BZX84W-B39-QF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84W-B39-QF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84W-B39-QF?
BZX84W-B39-QF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84W-B39-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-B39-QF?
For technical support, including BZX84W-B39-QF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84W-B39-QF requirements.
6.How does Aetrix verify that BZX84W-B39-QF is sourced from the original manufacturer or authorized distributors?
All BZX84W-B39-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-B39-QF meets industry standards.
7.What is the process for return or replacement of BZX84W-B39-QF?
All BZX84W-B39-QF units undergo pre-shipment inspection (PSI). If there is an issue with BZX84W-B39-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-B39-QF part is unused and in its original packaging.
Return procedure for BZX84W-B39-QF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84W-B39-QF Tags
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MMBZ5240B-7-F
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BZT52C5V6T-7
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MMSZ5231B-7-F
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MMSZ4682T1G
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BZT52C15S-7-F
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MM5Z5V1ST1G
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SMAZ12-13-F
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