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Nexperia USA Inc. BZX38450-B33-QX
- Part No.:
- BZX38450-B33-QX
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-76, SOD-323
- Datasheet:
-
BZX38450-B33-QX.pdf
- Description:
- DIODE ZENER 33V 300MW SOD323
- Quantity:
- Payment:
- Shipping:
Inventory:6,578
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Product details
Overview
BZX38450-B33-QX from Nexperia is a low-current Zener voltage regulator diode in SOD323 (SC-76) package, rated for 33 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-B33-QX datasheet, BZX38450-B33-QX pinout, BZX38450-B33-QX application, or BZX38450-B33-QX equivalent, this page delivers verified electrical characteristics, thermal resistance data, cathode/anode terminal mapping, and automotive-grade reliability context - all critical for low-bias regulation in battery-powered ECUs and sensor interfaces.
Technical Context
This device operates as a two-terminal shunt voltage reference, maintaining stable 33 V regulation under reverse bias at low test currents (50 µA), with differential resistance of 325 Ω at 5 mA and temperature coefficient of +0.05 mV/K. Its leakage behavior is optimized per AN90031 for fast switching and noise reduction.
Designed for surface-mount operation on FR4 PCBs with single-sided copper, it exhibits Rth(j-a) = 415 K/W and Rth(j-sp) = 110 K/W, supporting ambient operation from −55 °C to +150 °C and junction temperatures up to 150 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 33 V at IZ = 50 µA - precise regulation point for low-power bias networks |
| Tolerance | ±2 % - tight voltage accuracy enabling robust margining in automotive sensor supplies |
| Differential Resistance | 325 Ω at IZ = 5 mA - low dynamic impedance ensures stable output under small load variations |
| Forward Voltage | ≤ 0.9 V at IF = 10 mA - minimal forward drop for polarity-check or clamping functions |
| Power Dissipation | 300 mW at Tamb ≤ 25 °C - sufficient headroom for transient surges in compact SOD323 footprint |
| Junction Temperature Limit | 150 °C - supports under-hood automotive environments without derating at full power |
| AEC-Q101 Qualified | Yes - validated for automotive discrete semiconductor stress testing including HTGB, HTRB, and ESD |
Pinout & Package
Package: SOD323 (SC-76), plastic surface-mounted, 1.7 mm × 1.25 mm × 0.95 mm body, 1.3 mm lead pitch. Cathode identified by marking bar.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Cathode (K) | Connected to regulated output node; carries reverse current during Zener conduction |
| 2 | Anode (A) | Connected to ground or lower-potential rail; completes bias path for voltage reference operation |
Key Features
| Feature | Design Value |
|---|---|
| Low test current operation | Specified at 50 µA - enables ultra-low quiescent current regulation in battery-backed systems |
| Optimized leakage profile | Intentional minor rise per AN90031 - reduces switching noise in signal conditioning paths |
| Automotive qualification | AEC-Q101 compliant - meets stress test requirements for engine control, ADAS, and body electronics |
| Thermal performance | Rth(j-sp) = 110 K/W - efficient heat transfer to solder joint improves long-term reliability on FR4 |
Applications
| Engine Control Unit (ECU) Sensor Bias | Automotive Cabin Temperature Sensor |
|---|---|
Use Scenario: Providing stable 33 V reference to analog front-end of knock sensor interface circuitry in gasoline engine ECUs. IC Role / Device Role / Timing Role: Shunt voltage regulator establishing precision bias point for op-amp input stage and ADC reference divider. Use Value: ±2 % tolerance and low 50 µA test current minimize supply loading while maintaining signal integrity across −40 °C to +125 °C operating range. |
Use Scenario: Regulating excitation voltage for thermistor-based cabin air temperature sensing in HVAC control modules. IC Role / Device Role / Timing Role: Low-power Zener reference supplying fixed bias to thermistor bridge, enabling high-resolution resistance measurement. Use Value: Optimized leakage behavior reduces noise coupling into high-gain amplifier stages, improving temperature resolution below 0.1 °C. |
| ADAS Camera Module Power Sequencing | Electric Power Steering (EPS) Position Sensor |
Use Scenario: Generating clean 33 V auxiliary rail for image signal processor (ISP) power-on reset sequencing in surround-view camera systems. IC Role / Device Role / Timing Role: Standby-mode voltage clamp ensuring controlled ramp-up of ISP core voltage during cold start. Use Value: AEC-Q101 qualification and 150 °C junction rating guarantee reliable startup under repeated thermal cycling in dashboard mounting locations. |
Use Scenario: Stabilizing reference voltage for resolver-to-digital converter (RDC) excitation in EPS motor position feedback circuits. IC Role / Device Role / Timing Role: Precision shunt regulator delivering low-noise 33 V to resolver primary winding driver stage. Use Value: 325 Ω differential resistance maintains regulation stability despite ripple from PWM-driven gate drivers nearby on same PCB. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX384-C33-Q | ±5 % tolerance, higher leakage at VR = 33 V (0.05 µA vs. 0.05 µA), identical SOD323 package | Suitable for non-critical bias where cost sensitivity outweighs voltage accuracy | Select when ±5 % regulation tolerance is acceptable and AEC-Q101 compliance remains required |
| MMSZ5261B-TP | ±5 % tolerance, 300 mW rating, but not AEC-Q101 qualified; VF = 0.9 V at 10 mA matches | Limited to industrial or consumer applications lacking automotive qualification mandates | Choose only for non-automotive designs where qualification overhead is unnecessary and cost is prioritized |
Compared with BZX38450-B33-QX, the BZX384-C33-Q trades voltage accuracy for broader tolerance compliance in same-qualified automotive use, while MMSZ5261B-TP omits AEC-Q101 entirely - making the BZX38450-B33-QX the sole option meeting both ±2 % precision and automotive stress validation.
Availability
BZX38450-B33-QX is available at Aetrix Electronics and suitable for automotive ECU design, ADAS sensor biasing, and electric power steering position sensing requiring stable component supply with full traceability and lifecycle continuity.
Supply support for BZX38450-B33-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 Zener diode product line, engineered specifically for low-current, high-stability voltage regulation in safety-critical and thermally demanding vehicle subsystems.
FAQ
What is the maximum reverse voltage (VR) this diode can withstand before breakdown?
The BZX38450-B33-QX has a nominal Zener voltage of 33 V at 50 µA, with guaranteed minimum/maximum working voltage of 32.3 V / 33.7 V. It is not rated for continuous operation above its specified VZ; exceeding 33.7 V risks uncontrolled conduction and thermal runaway unless current-limited externally.
Does this part support reflow soldering, and what footprint is recommended?
Yes, BZX38450-B33-QX is qualified for reflow soldering per JEDEC J-STD-020. The recommended footprint is shown in Figure 10 of the datasheet: 0.5 mm × 0.6 mm solder lands, 0.6 mm solder resist opening, and 2.2 mm overall pad length - optimized for SOD323 (SC-76) thermal and mechanical reliability.
How does the "B" suffix differ from "C" in the BZX38450-Q series?
The "B" suffix denotes ±2 % tolerance on nominal Zener voltage (e.g., 32.3 V to 33.7 V for 33 V), while "C" indicates approximately ±5 % tolerance (e.g., 31.35 V to 34.65 V). Both share identical package, thermal specs, and AEC-Q101 qualification - only voltage accuracy differs.
Can this diode be used in parallel for higher power handling?
No - Zener diodes exhibit negative temperature coefficients and mismatched VZ tolerances, causing current hogging and thermal instability when paralleled. For >300 mW dissipation, use a single higher-rated device or active regulation instead of parallel BZX38450-B33-QX units.
BZX38450-B33-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):
- 33 V
- Tolerance:
- ±2%
- Power - Max:
- 300 mW
- Impedance (Max) (Zzt):
- 80 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 25 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-B33-QX FAQ
1.How can I place an order for BZX38450-B33-QX through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX38450-B33-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-B33-QX reliable?
The price and inventory of BZX38450-B33-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-B33-QX is usually 5 days.
3.What payment methods are accepted for BZX38450-B33-QX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX38450-B33-QX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX38450-B33-QX?
BZX38450-B33-QX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX38450-B33-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-B33-QX?
For technical support, including BZX38450-B33-QX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX38450-B33-QX requirements.
6.How does Aetrix verify that BZX38450-B33-QX is sourced from the original manufacturer or authorized distributors?
All BZX38450-B33-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-B33-QX meets industry standards.
7.What is the process for return or replacement of BZX38450-B33-QX?
All BZX38450-B33-QX units undergo pre-shipment inspection (PSI). If there is an issue with BZX38450-B33-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-B33-QX part is unused and in its original packaging.
Return procedure for BZX38450-B33-QX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX38450-B33-QX Tags
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MMBZ5240B-7-F
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