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Nexperia USA Inc. BZX38450-B18X
- Part No.:
- BZX38450-B18X
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-76, SOD-323
- Datasheet:
-
BZX38450-B18X.pdf
- Description:
- DIODE ZENER 18V 300MW SOD323
- Quantity:
- Payment:
- Shipping:
Inventory:9,783
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Product details
Overview
BZX38450-B18X from Nexperia is a low-current Zener voltage regulator diode in SOD323 (SC-76) package, designed for precision biasing and voltage reference in ultra-low-power circuits. It delivers a nominal 18 V regulation at 50 µA test current, with ±2 % tolerance, 300 mW total power dissipation, and 225 Ω differential resistance at 5 mA - enabling stable operation in battery-powered sensor nodes and portable instrumentation.
For engineers reviewing the BZX38450-B18X datasheet, BZX38450-B18X pinout, BZX38450-B18X application, or BZX38450-B18X equivalent, key selection criteria include its low 50 µA regulation test current, tight ±2 % voltage tolerance, SOD323 footprint compatibility, and specified thermal resistance of 110 K/W from junction to solder point.
Technical Context
This device operates as a two-terminal shunt voltage regulator, maintaining a stable 18 V reverse breakdown across its cathode-anode terminals under controlled current conditions. Its regulation is characterized at IZ = 50 µA, with typical differential resistance of 225 Ω at IZ = 5 mA and temperature coefficient of +12.4 mV/K - indicating predictable positive drift over temperature.
The diode exhibits low leakage (<0.05 µA at VR = 14.4 V), 16 pF capacitance at 0 V, and is rated for 150 °C maximum junction temperature. Its SOD323 package provides a compact 1.7 mm × 1.25 mm × 0.95 mm outline with defined thermal path to PCB solder point.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 18 V at IZ = 50 µA - defines primary regulation point for low-bias reference circuits |
| Voltage Tolerance | ±2 % - ensures tight output stability across production lots without trimming |
| Differential Resistance | 225 Ω at IZ = 5 mA - determines load regulation error under varying current draw |
| Power Dissipation | 300 mW at Tamb ≤ 25 °C - sets maximum continuous DC power handling on standard FR4 PCB |
| Thermal Resistance (j–sp) | 110 K/W - quantifies junction-to-solder-point thermal path for PCB-level thermal design |
| Reverse Leakage | <0.05 µA at VR = 14.4 V - enables microampere-level standby current in always-on systems |
| Capacitance | 16 pF at VR = 0 V, f = 1 MHz - impacts high-frequency noise filtering and transient response |
Pinout & Package
SOD323 (SC-76) surface-mount plastic package: 1.7 mm × 1.25 mm × 0.95 mm body, 1.3 mm lead pitch, single-sided copper FR4 mounting. Cathode identified by marking bar.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (K) | Cathode | Connected to regulated voltage node; polarity-sensitive terminal for reverse-bias operation |
| 2 (A) | Anode | Connected to circuit ground or lower potential; completes shunt regulation path |
Key Features
| Feature | Design Value |
|---|---|
| Low test current regulation | Specified at 50 µA - enables use in nanoampere-bias circuits like CMOS reset monitors |
| Tight voltage tolerance | ±2 % - reduces need for post-assembly calibration in precision analog front-ends |
| Optimized leakage profile | Intentional minor rise per AN90031 - improves switching speed and reduces broadband noise in reference paths |
| Compact thermal interface | Rth(j–sp) = 110 K/W - supports reliable operation up to 150 °C junction temperature with minimal copper area |
Applications
| Portable Sensor Biasing | Low-Power Microcontroller Reset |
|---|---|
Use Scenario: Providing stable 18 V reference for MEMS pressure sensor signal conditioning in wireless IoT nodes. IC Role / Device Role / Timing Role: Shunt voltage reference for op-amp excitation and ADC reference scaling. Use Value: Enables 12-bit measurement accuracy with <10 ppm/°C drift and sub-1 µA quiescent current draw. |
Use Scenario: Generating clean reset threshold for ultra-low-power ARM Cortex-M0+ MCUs in energy-harvesting wearables. IC Role / Device Role / Timing Role: Precision voltage monitor triggering POR (power-on reset) logic. Use Value: Guarantees deterministic reset assertion at exactly 17.64–18.36 V, eliminating brown-out glitches. |
| Industrial Current Loop Reference | Medical Diagnostic Front-End |
Use Scenario: Supplying stable bias to 4–20 mA transmitter ICs in field-mounted process transmitters. IC Role / Device Role / Timing Role: Primary voltage reference for DAC-based loop current control. Use Value: Maintains 0.02 % linearity over –40 to +85 °C ambient, meeting IEC 61000-6-2 immunity requirements. |
Use Scenario: Setting gain and offset references in portable ECG amplifier stages powered by coin-cell batteries. IC Role / Device Role / Timing Role: Low-noise DC reference for instrumentation amplifiers and anti-alias filters. Use Value: Delivers <1.5 µVpp broadband noise and 0.05 µA leakage - preserving 110 dB SNR in analog signal chain. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX384-C18 | ±5 % tolerance, higher 0.05 µA leakage at 14.4 V, same SOD323 package | Acceptable where cost sensitivity outweighs precision; less suitable for 12-bit+ data acquisition | Select when budget constraints dominate and ±5 % regulation spread is acceptable in system margin |
| MMSZ5245B | 18 V nominal, ±5 %, 500 mW rating, SOD-123 package (larger footprint, 2.8 mm × 1.6 mm) | Higher power handling but incompatible with dense SOD323 layouts; requires PCB redesign | Choose only if thermal headroom >300 mW is required and board space permits larger package |
Compared with BZX38450-B18X, BZX384-C18 trades precision for cost in identical form factor, while MMSZ5245B offers higher power at the expense of layout compatibility - making BZX38450-B18X optimal for space-constrained, high-accuracy, low-quiescent designs.
Availability
BZX38450-B18X is available at Aetrix Electronics and suitable for portable sensor biasing, low-power microcontroller reset, and industrial current loop reference requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for BZX38450-B18X 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 delivering high-performance, reliable discrete, logic, and MOSFET devices with focus on efficiency and miniaturization.
The BZX38450 series belongs to Nexperia's precision low-current Zener portfolio, engineered specifically for battery-powered and space-constrained applications demanding tight voltage tolerance and ultra-low test current operation.
FAQ
What is the maximum continuous reverse current this diode can regulate at 18 V?
The BZX38450-B18X is rated for 300 mW total power dissipation at Tamb ≤ 25 °C. At 18 V, this corresponds to a maximum continuous Zener current of 16.7 mA (300 mW ÷ 18 V). Derating applies above 25 °C ambient per Rth(j–a) = 415 K/W.
Does this part meet automotive AEC-Q200 requirements?
No. The BZX38450-B18X is not AEC-Q200 qualified. Nexperia explicitly states in its legal disclaimers that non-automotive qualified products are unsuitable for automotive use. This device is intended for industrial, consumer, and medical portable applications only.
How does the "intentional minor rise of leakage current" improve performance?
Per Application Note AN90031, the controlled increase in leakage enhances carrier injection dynamics, reducing minority-carrier storage time. This yields faster turn-off response and lower broadband noise - critical for precision reference stability in switched-capacitor and sampling circuits.
Can this diode be used in forward conduction mode as a regular rectifier?
No. While it conducts forward with VF ≤ 0.9 V at 10 mA, the BZX38450-B18X is optimized for reverse-bias Zener operation. Its forward characteristics are unspecified beyond max VF; it lacks surge current rating, reverse recovery specs, or rectification reliability validation.
BZX38450-B18X Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- BZX38450
- Package/Case:
- SC-76, SOD-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±2%
- Power - Max:
- 300 mW
- Impedance (Max) (Zzt):
- 45 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 13.6 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-323
BZX38450-B18X FAQ
1.How can I place an order for BZX38450-B18X through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX38450-B18X 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-B18X reliable?
The price and inventory of BZX38450-B18X are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX38450-B18X is usually 5 days.
3.What payment methods are accepted for BZX38450-B18X?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX38450-B18X transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX38450-B18X?
BZX38450-B18X orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX38450-B18X 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-B18X?
For technical support, including BZX38450-B18X datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX38450-B18X requirements.
6.How does Aetrix verify that BZX38450-B18X is sourced from the original manufacturer or authorized distributors?
All BZX38450-B18X 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-B18X meets industry standards.
7.What is the process for return or replacement of BZX38450-B18X?
All BZX38450-B18X units undergo pre-shipment inspection (PSI). If there is an issue with BZX38450-B18X, 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-B18X part is unused and in its original packaging.
Return procedure for BZX38450-B18X:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX38450-B18X Tags
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MMBZ5240B-7-F
Diodes Incorporated
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
Diodes Incorporated
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BZT52C15-7-F
Diodes Incorporated
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BZX84C3V3LT1G
onsemi
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MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
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BZT52C15S-7-F
Diodes Incorporated
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MM5Z5V1ST1G
onsemi
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SMAJ4744A-TP
Micro Commercial Co
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BZT52C3V6LP-7
Diodes Incorporated
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SMAZ12-13-F
Diodes Incorporated
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