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Nexperia USA Inc. BZX38450-B39-QX
- Part No.:
- BZX38450-B39-QX
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-76, SOD-323
- Datasheet:
-
BZX38450-B39-QX.pdf
- Description:
- DIODE ZENER 39V 300MW SOD323
- Quantity:
- Payment:
- Shipping:
Inventory:8,582
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Product details
Overview
BZX38450-B39-QX from Nexperia is a low-current Zener voltage regulator diode in SOD323 (SC-76) package, rated for 39 V nominal working voltage at 50 µA test current, with ±2 % tolerance, 300 mW total power dissipation, and AEC-Q101 qualification for automotive use.
For engineers reviewing the BZX38450-B39-QX datasheet, BZX38450-B39-QX pinout, BZX38450-B39-QX application, or BZX38450-B39-QX equivalent, this page delivers verified electrical characteristics, thermal resistance (Rth(j-a) = 415 K/W), differential resistance (350 Ω max at IZ = 2 mA), temperature coefficient (+0.05 mV/K), and reverse leakage behavior under defined bias conditions.
Technical Context
This Zener diode operates in reverse breakdown mode with a specified nominal Zener voltage of 39 V at IZ = 50 µA, exhibiting a tight ±2 % tolerance (B-series) and low dynamic impedance (≤350 Ω at IZ = 2 mA). Its design targets stable reference generation under minimal bias current.
Thermal performance is defined by junction-to-ambient resistance of 415 K/W on FR4 PCB and junction-to-solder-point resistance of 110 K/W, enabling reliable operation up to 150 °C junction temperature. It features intentional minor leakage optimization per AN90031 for fast switching and noise reduction.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 38.2 V to 39.8 V at IZ = 50 µA - defines precise regulation point for low-power reference circuits |
| Tolerance | ±2 % - ensures consistent voltage accuracy across production lots without post-selection |
| Differential Resistance (rdiff) | ≤350 Ω at IZ = 2 mA - maintains low output impedance for stable regulation under small load variations |
| Power Dissipation (Ptot) | 300 mW at Tamb ≤ 25 °C - supports continuous operation in compact SMD layouts with standard FR4 PCB |
| Forward Voltage (VF) | ≤0.9 V at IF = 10 mA - enables predictable forward conduction behavior during polarity-reversal transients |
| Junction Temperature (Tj) | −55 °C to +150 °C - validated for under-hood automotive environments and industrial ambient extremes |
| AEC-Q101 Qualified | Yes - certified for automotive-grade reliability including HTGB, HTRB, and temperature cycling stress tests |
Pinout & Package
The BZX38450-B39-QX is housed in a SOD323 (SC-76) surface-mount plastic package measuring 1.7 mm × 1.25 mm × 0.95 mm, with 1.3 mm lead pitch and cathode marked by a bar on the device body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Cathode (K) | Connected to regulated output node; marking bar identifies this terminal for correct PCB orientation |
| 2 | Anode (A) | Connected to ground or lower-potential rail; reverse-biased configuration establishes Zener breakdown |
Key Features
| Feature | Design Value |
|---|---|
| Low Test Current Operation | Specified at 50 µA - enables use in ultra-low-power battery-backed systems where quiescent current must be minimized |
| Automotive Qualification | AEC-Q101 compliant - guarantees robustness against thermal shock, humidity, and mechanical stress in vehicle ECUs |
| Optimized Leakage Profile | Intentional minor rise per AN90031 - reduces switching noise and improves transient response in feedback paths |
| Compact SMD Package | SOD323 footprint - allows high-density placement in space-constrained modules such as ADAS sensors and body control units |
Applications
| Automotive Body Control Module | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Stable 39 V reference for microcontroller ADC input scaling in door module voltage monitoring. IC Role / Device Role / Timing Role: Zener regulator providing precision bias for analog front-end circuitry. Use Value: Tight ±2 % tolerance ensures consistent measurement accuracy across temperature and unit variance without calibration. |
Use Scenario: Reference voltage source for 4–20 mA transmitter loop-powered sensor interface. IC Role / Device Role / Timing Role: Passive voltage clamp and regulation element in two-wire current loop design. Use Value: 300 mW power rating and 415 K/W thermal resistance allow reliable operation on minimal copper area in isolated sensor PCBs. |
| Portable Medical Diagnostic Device | Automotive Infotainment Power Sequencing |
Use Scenario: Low-current bias supply for op-amp comparators in handheld ECG signal amplification stage. IC Role / Device Role / Timing Role: Voltage reference generator operating at 50 µA test current to extend battery life. Use Value: Specified behavior at 50 µA enables direct integration into micro-power designs without external current boosting. |
Use Scenario: Voltage supervision node for 3.3 V/5 V rail sequencing in head unit power management IC startup sequence. IC Role / Device Role / Timing Role: Reverse-biased Zener used in discrete reset threshold detection circuit. Use Value: AEC-Q101 qualification and −55 °C to +150 °C operating range ensure functional integrity during cold cranking and hot soak conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX38450-C39-Q | ±5 % tolerance (vs. ±2 %), identical VZ range (37.05–40.95 V), same SOD323 package | Acceptable where cost sensitivity outweighs precision requirement; higher IR at VR = 0 V | Select when tighter tolerance is unnecessary and BOM cost reduction is prioritized over reference stability |
| MMSZ5257B-7-F | 39 V nominal, ±5 %, 500 mW Ptot, SOD-123 package (larger footprint), no AEC-Q101 qualification | Limited to non-automotive industrial use due to lack of automotive qualification and higher thermal resistance | Choose only for non-automotive applications requiring higher power margin and where board space permits larger package |
Compared with BZX38450-C39-Q, the BZX38450-B39-QX offers superior voltage accuracy critical for calibrated sensing; versus MMSZ5257B-7-F, it provides automotive-grade reliability and smaller footprint but lower absolute power handling.
Availability
BZX38450-B39-QX is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor interfaces, portable medical diagnostics, and infotainment power sequencing requiring stable component supply with traceable sourcing and lifecycle continuity.
Supply support for BZX38450-B39-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 logic, discrete, and MOSFET solutions, with leadership in automotive-qualified components.
The BZX38450-Q series belongs to Nexperia's automotive-grade Zener diode product line, engineered specifically for precision low-current voltage regulation in harsh-environment electronic control units.
FAQ
What is the maximum reverse current (IR) for BZX38450-B39-QX at VR = 0 V?
The maximum reverse current is 0.05 µA at VR = 0 V and Tj = 25 °C, as specified in Table 9 of the datasheet. This ultra-low leakage supports stable reference performance in high-impedance bias networks and extends battery life in always-on subsystems.
Can BZX38450-B39-QX be used in parallel for higher power dissipation?
No - Zener diodes exhibit negative temperature coefficients and mismatched VZ tolerances, causing current hogging and thermal runaway when paralleled. For higher power, select a single higher-rated device or implement active regulation instead.
Is the SOD323 package compatible with standard reflow soldering profiles?
Yes - Nexperia provides dedicated reflow footprint data (Fig. 10) and qualifies the device for JEDEC J-STD-020 moisture sensitivity level 1. Peak reflow temperature must not exceed 260 °C for ≤30 seconds, with ramp rates within IPC/JEDEC specifications.
How does the "intentional minor rise of leakage current" affect circuit performance?
Per AN90031, this controlled increase reduces switching noise and improves transient response in feedback loops by minimizing minority-carrier storage effects. It does not compromise DC regulation accuracy or long-term reliability under rated conditions.
BZX38450-B39-QX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- BZX38450-Q
- Package/Case:
- SC-76, SOD-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 39 V
- Tolerance:
- ±2%
- Power - Max:
- 300 mW
- Impedance (Max) (Zzt):
- 130 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 29.6 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:
- SOD-323
BZX38450-B39-QX FAQ
1.How can I place an order for BZX38450-B39-QX through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX38450-B39-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 BZX38450-B39-QX reliable?
The price and inventory of BZX38450-B39-QX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX38450-B39-QX is usually 5 days.
3.What payment methods are accepted for BZX38450-B39-QX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX38450-B39-QX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX38450-B39-QX?
BZX38450-B39-QX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX38450-B39-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 BZX38450-B39-QX?
For technical support, including BZX38450-B39-QX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX38450-B39-QX requirements.
6.How does Aetrix verify that BZX38450-B39-QX is sourced from the original manufacturer or authorized distributors?
All BZX38450-B39-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 BZX38450-B39-QX meets industry standards.
7.What is the process for return or replacement of BZX38450-B39-QX?
All BZX38450-B39-QX units undergo pre-shipment inspection (PSI). If there is an issue with BZX38450-B39-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 BZX38450-B39-QX part is unused and in its original packaging.
Return procedure for BZX38450-B39-QX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX38450-B39-QX Tags
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MMSZ5231B-7-F
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MMSZ5245BS-7-F
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BZT52C15S-7-F
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MM5Z5V1ST1G
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