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Nexperia USA Inc. BZX8450-B3V9-QR
- Part No.:
- BZX8450-B3V9-QR
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BZX8450-B3V9-QR.pdf
- Description:
- DIODE ZENER 3.9V 250MW TO236AB
- Quantity:
- Payment:
- Shipping:
Inventory:9,225
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Product details
Overview
BZX8450-B3V9-QR from Nexperia is a low-current Zener voltage regulator diode in SOT23 package, designed for precision biasing and voltage reference in portable electronics. It delivers 3.9 V nominal regulation at 50 µA test current, with ±2 % tolerance, 600 Ω differential resistance at 5 mA, and 2.5 µA reverse leakage at 3.0 V, enabling stable operation in battery-powered sensor nodes and automotive microcontroller power rails.
For engineers reviewing the BZX8450-B3V9-QR datasheet, BZX8450-B3V9-QR pinout, BZX8450-B3V9-QR application, or BZX8450-B3V9-QR equivalent, this page provides verified electrical characteristics, AEC-Q101 qualification status, thermal resistance data (Rth(j-a) = 500 K/W), and direct comparison to BZX8450-C3V9-Q and BZX8450-B3V9-QL alternatives.
Technical Context
This Zener diode operates in reverse breakdown mode with a specified working voltage of 3.82 V to 3.98 V at IZ = 50 µA, exhibiting a temperature coefficient of −2.7 mV/K and diode capacitance of 150 pF at VR = 0 V and f = 1 MHz. Its low 50 µA test current enables ultra-low quiescent current design in always-on circuits.
The device features intentional minor leakage current optimization per AN90031 for fast switching and noise reduction, and is qualified to AEC-Q101 for automotive underhood and infotainment applications. Thermal performance is defined for FR4 PCB mounting with single-sided 70 μm copper and standard footprint.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 3.9 V at IZ = 50 µA - sets precise reference point for low-power analog sensing and MCU reset circuits |
| Voltage Tolerance | ±2 % (B-series) - ensures tight regulation across production batches without post-assembly trimming |
| Differential Resistance | 600 Ω max at IZ = 5 mA - defines output impedance affecting load regulation error in feedback paths |
| Reverse Leakage Current | 2.5 µA max at VR = 3.0 V - enables <1 µA standby current in battery-backed real-time clocks |
| Forward Voltage | 0.9 V max at IF = 10 mA - supports low-loss polarity protection when used in series with logic inputs |
| Total Power Dissipation | 250 mW at Tamb ≤ 25 °C - limits thermal rise on compact PCBs without heatsinking |
| Junction Temperature | 150 °C max - allows operation in under-hood automotive environments up to +125 °C ambient |
Pinout & Package
Package: SOT23 plastic surface-mount package (2.9 mm × 1.3 mm × 1.0 mm body, 1.9 mm pin pitch), qualified for reflow and wave soldering per Figures 10–11.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode (A) | Connects to lower-potential node; reverse-biased during regulation; must be routed with minimal trace inductance for noise-sensitive references |
| 2 | Not Connected (n.c.) | Internally unconnected; must remain floating-no PCB pad connection or routing allowed |
| 3 | Cathode (K) | Connects to higher-potential node; serves as regulated output reference point; thermal path to PCB via cathode tab (Rth(j-sp) = 330 K/W) |
Key Features
| Feature | Design Value |
|---|---|
| Low test current operation | Specified at 50 µA - enables use in nanoampere-bias circuits like piezoelectric sensor interfaces |
| AEC-Q101 qualification | Qualified for automotive applications - supports deployment in engine control units and ADAS domain controllers without additional reliability screening |
| Optimized leakage profile | Intentional minor IR rise per AN90031 - reduces high-frequency noise and improves transient response in LDO feedback networks |
| Tight voltage tolerance | ±2 % (B-series) - eliminates need for external trimming resistors in factory-calibrated medical wearables |
| Thermal resistance control | Rth(j-a) = 500 K/W on FR4 - enables accurate junction temperature estimation for thermal derating in sealed enclosures |
Applications
| Automotive Microcontroller Reset Circuit | Portable Gas Sensor Bias Supply |
|---|---|
Use Scenario: Provides clean 3.9 V reference to reset supervisor IC in automotive body control module operating from 12 V battery with load dump transients. IC Role / Device Role / Timing Role: Zener voltage reference establishing threshold for reset assertion; replaces larger 3-pin shunt regulators to save board space. Use Value: ±2 % tolerance ensures consistent reset voltage across temperature (−40 °C to +125 °C), while 250 mW rating handles brief overvoltage surges without degradation. |
Use Scenario: Supplies stable bias voltage to electrochemical CO sensor in handheld air quality monitor powered by CR2032 coin cell. IC Role / Device Role / Timing Role: Low-current Zener reference generating fixed bias for sensor electrode drive; operates continuously in sleep mode. Use Value: 50 µA test current enables <0.5 µA total quiescent draw, extending battery life beyond 2 years; 150 pF capacitance avoids signal coupling into sensitive analog front-end. |
| Industrial PLC Analog Input Protection | Medical Wearable Reference Divider |
Use Scenario: Clamps input voltage to 3.9 V before ADC in programmable logic controller analog input channel exposed to field wiring ESD events. IC Role / Device Role / Timing Role: Shunt overvoltage protector limiting fault energy into precision op-amp buffer stage. Use Value: 40 W non-repetitive peak power dissipation (tp = 100 µs) absorbs IEC 61000-4-2 contact discharge without failure; n.c. pin prevents parasitic coupling. |
Use Scenario: Forms top leg of resistor divider feeding 1.95 V reference to ultra-low-power ECG analog front-end in patch-style cardiac monitor. IC Role / Device Role / Timing Role: Precision Zener element defining upper voltage node in ratiometric reference chain. Use Value: −2.7 mV/K temperature coefficient minimizes drift-induced baseline wander; 600 Ω dynamic resistance ensures <0.1 % divider error under varying load currents. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX8450-C3V9-Q | ±5 % tolerance (vs. ±2 %), 150 pF capacitance unchanged, same 3.82–3.98 V min/max range but wider distribution | Acceptable where calibration occurs downstream (e.g., MCU ADC offset correction); not suitable for uncalibrated analog sensors | Select for cost-sensitive consumer IoT devices where post-production software compensation is available |
| BZX8450-B3V9-QL | Same electrical specs but halogen-free, RoHS-compliant marking; identical thermal and electrical behavior | No functional difference; required only for strict environmental compliance in EU medical or industrial equipment | Select when regulatory documentation (DoC, IPC-1752) mandates halogen-free materials |
Compared with BZX8450-B3V9-QR, the C-series offers broader tolerance at lower cost for calibrated systems, while the -QL variant adds halogen-free compliance without altering regulation performance-making the QR version optimal for uncalibrated automotive and portable analog designs requiring guaranteed ±2 % accuracy.
Availability
BZX8450-B3V9-QR is available at Aetrix Electronics and suitable for automotive microcontroller reset circuits, portable gas sensor bias supplies, and industrial PLC analog input protection requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for BZX8450-B3V9-QR 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 advanced packaging.
The BZX8450-Q series belongs to Nexperia's AEC-Q101-qualified Zener diode product line, engineered specifically for low-current voltage reference and regulation in space-constrained, battery-operated, and automotive-grade electronic systems.
FAQ
What is the maximum reverse voltage that BZX8450-B3V9-QR can withstand before breakdown?
The BZX8450-B3V9-QR has a nominal Zener voltage of 3.9 V, with minimum and maximum values of 3.82 V and 3.98 V respectively at IZ = 50 µA. It does not have a separate "breakdown" threshold-it enters controlled reverse conduction within this specified range. The absolute maximum reverse voltage is limited by the 250 mW power dissipation rating and thermal constraints, not a hard voltage limit.
Can BZX8450-B3V9-QR be used in forward-biased configuration as a regular diode?
Yes, it functions as a standard silicon diode in forward bias, with VF ≤ 0.9 V at IF = 10 mA. However, its forward characteristics are not optimized or fully characterized beyond this single point; for dedicated rectification or clamping, purpose-built signal diodes like BAS16 offer superior speed and consistency.
How does the "n.c." pin (Pin 2) affect PCB layout and thermal design?
Pin 2 is internally not connected and must remain electrically floating-no trace, pad, or ground pour should contact it. This prevents unintended parasitic coupling and ensures thermal performance aligns with the published Rth(j-a) = 500 K/W value, which assumes only Pins 1 and 3 are soldered to the PCB per standard SOT23 footprint guidelines.
Is BZX8450-B3V9-QR suitable for use in a precision voltage reference circuit requiring <10 ppm/°C stability?
No. With a temperature coefficient of −2.7 mV/K, its drift is approximately −690 ppm/°C relative to 3.9 V-far exceeding 10 ppm/°C requirements. It is intended for general-purpose regulation and biasing, not metrology-grade references; for high-stability applications, consider bandgap-based references like REF3039 or LT1009.
BZX8450-B3V9-QR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- BZX8450-Q
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 3.9 V
- Tolerance:
- ±2%
- Power - Max:
- 250 mW
- Impedance (Max) (Zzt):
- 95 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 2 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:
- TO-236AB
BZX8450-B3V9-QR FAQ
1.How can I place an order for BZX8450-B3V9-QR through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX8450-B3V9-QR 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 BZX8450-B3V9-QR reliable?
The price and inventory of BZX8450-B3V9-QR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX8450-B3V9-QR is usually 5 days.
3.What payment methods are accepted for BZX8450-B3V9-QR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX8450-B3V9-QR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX8450-B3V9-QR?
BZX8450-B3V9-QR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX8450-B3V9-QR 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 BZX8450-B3V9-QR?
For technical support, including BZX8450-B3V9-QR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX8450-B3V9-QR requirements.
6.How does Aetrix verify that BZX8450-B3V9-QR is sourced from the original manufacturer or authorized distributors?
All BZX8450-B3V9-QR 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 BZX8450-B3V9-QR meets industry standards.
7.What is the process for return or replacement of BZX8450-B3V9-QR?
All BZX8450-B3V9-QR units undergo pre-shipment inspection (PSI). If there is an issue with BZX8450-B3V9-QR, 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 BZX8450-B3V9-QR part is unused and in its original packaging.
Return procedure for BZX8450-B3V9-QR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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