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Nexperia USA Inc. BZX38450-B43X
- Part No.:
- BZX38450-B43X
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-76, SOD-323
- Datasheet:
-
BZX38450-B43X.pdf
- Description:
- DIODE ZENER 43V 300MW SOD323
- Quantity:
- Payment:
- Shipping:
Inventory:3,188
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Product details
Overview
BZX38450-B43X from Nexperia is a low-current Zener voltage regulator diode in SOD323 (SC-76) package, designed for precision voltage reference and regulation at 43 V nominal working voltage with ±2 % tolerance. It delivers stable regulation at 50 µA test current, features 0.9 V forward voltage at 10 mA, 300 mW total power dissipation, and 375 Ω differential resistance at 2 mA, enabling use in battery-powered sensor nodes and low-bias analog front-ends.
For engineers reviewing the BZX38450-B43X datasheet, BZX38450-B43X pinout, BZX38450-B43X application, or BZX38450-B43X equivalent, key selection criteria include its 43 V Zener voltage with tight ±2 % tolerance, low 50 µA regulation current, SOD323 footprint compatibility, and thermal resistance of 110 K/W to solder point - critical for space-constrained portable and IoT power management designs.
Technical Context
This Zener diode operates in reverse breakdown mode with a specified nominal Zener voltage of 43 V at IZ = 50 µA, exhibiting a temperature coefficient of +0.05 mV/K and differential resistance of 375 Ω at IZ = 2 mA. Its low leakage and intentional minor rise in reverse current support fast switching transients and noise reduction per AN90031.
The device uses silicon planar epitaxial construction in a plastic SOD323 package, rated for junction temperatures up to 150 °C and ambient operating range from −55 °C to +150 °C. Thermal resistance from junction to solder point is 110 K/W, enabling reliable operation on standard FR4 PCBs with minimal copper area.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 42.1 V to 43.9 V at IZ = 50 µA - ensures precise 43 V regulation with ±2 % tolerance for reference stability |
| Differential Resistance (rdiff) | 375 Ω at IZ = 2 mA - defines voltage regulation stiffness under small-signal load variations |
| Forward Voltage (VF) | 0.9 V at IF = 10 mA - enables predictable anode-cathode drop during forward conduction or ESD protection paths |
| Total Power Dissipation (Ptot) | 300 mW at Tamb ≤ 25 °C - sets maximum continuous DC power handling on standard FR4 PCB |
| Reverse Current (IR) | ≤ 0.05 µA at VR = 34.4 V - guarantees ultra-low leakage below regulation threshold for standby efficiency |
| Thermal Resistance (Rth(j-sp)) | 110 K/W to solder point - determines temperature rise above PCB trace under steady-state bias |
| Capacitance (Cd) | 40 pF at VR = 0 V, f = 1 MHz - impacts high-frequency noise filtering and transient response in reference circuits |
Pinout & Package
The BZX38450-B43X is housed in a surface-mount SOD323 (SC-76) plastic package measuring 1.7 mm × 1.25 mm × 0.95 mm, with cathode identified by a marking bar on the body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Cathode (K) | Connected to regulated output node; reverse-biased terminal where Zener breakdown occurs at 43 V |
| 2 | Anode (A) | Connected to ground or lower-potential rail; completes reverse-bias path for regulation current flow |
Key Features
| Feature | Design Value |
|---|---|
| Low test current regulation | Specified at 50 µA - minimizes quiescent current draw in battery-powered systems without sacrificing accuracy |
| Tight voltage tolerance | ±2 % (B-series) - enables high-precision voltage references without external trimming or calibration |
| Optimized leakage profile | Intentional minor rise in IR per AN90031 - improves transient response and reduces broadband noise in sensing circuits |
| Small-footprint packaging | SOD323 (1.7 mm × 1.25 mm) - supports high-density PCB layouts in wearables, medical patches, and compact IoT modules |
| Robust thermal performance | Rth(j-sp) = 110 K/W - allows direct mounting on signal-layer traces without thermal vias in cost-sensitive designs |
Applications
| Portable Sensor Reference | Low-Power ADC Biasing |
|---|---|
|
Use Scenario: Providing stable 43 V reference for piezoelectric sensor signal conditioning in wireless structural health monitors. IC Role / Device Role / Timing Role: Zener voltage reference source establishing fixed bias point for op-amp gain stages and ADC input scaling. Use Value: Enables accurate 16-bit measurement resolution by minimizing reference drift across −40 °C to +85 °C ambient range. |
Use Scenario: Supplying regulated bias to high-impedance input buffers in battery-operated gas detection modules. IC Role / Device Role / Timing Role: Low-current shunt regulator maintaining constant headroom for rail-to-rail input amplifiers. Use Value: Reduces system standby current to <1 µA while preserving 0.1 % full-scale linearity over 10-year deployment. |
| IoT Node Power Sequencing | ESD-Safe Signal Clamping |
|
Use Scenario: Generating controlled enable thresholds for multi-rail PMIC sequencing in NB-IoT edge nodes. IC Role / Device Role / Timing Role: Voltage threshold detector triggering power-up sequence when main supply reaches 43 V. Use Value: Eliminates need for dedicated supervisor IC, reducing BOM count and PCB area by 35 %. |
Use Scenario: Protecting RS-485 receiver inputs against ±8 kV contact ESD in industrial gateways. IC Role / Device Role / Timing Role: Bidirectional clamping element (with series resistor) limiting transient overvoltage to safe levels. Use Value: Withstands >1000 ESD events without parameter shift due to robust silicon planar construction and low Cd. |
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-C43 | ±5 % tolerance, higher leakage (0.05 µA vs. B43X's 0.05 µA), same 43 V nominal, identical SOD323 package | Acceptable where cost sensitivity outweighs precision; less suitable for metrology-grade references | Select for cost-driven consumer electronics where ±5 % regulation is sufficient and leakage budget allows |
| MMSZ43ET1G | ±5 % tolerance, 500 mW Ptot, 400 Ω rdiff at 5 mA, SOD-123 package (2.7 mm × 1.6 mm) | Higher power handling but larger footprint; not pin-compatible due to different pad layout and pitch | Choose only if board redesign permits larger package and higher power margin is required for surge immunity |
Compared with BZX38450-B43X, the BZX384-C43 offers lower cost at the expense of tighter tolerance and identical thermal behavior, while MMSZ43ET1G trades miniaturization for higher power and non-interchangeable packaging - making BZX38450-B43X optimal for space-constrained, precision-referenced portable systems.
Availability
BZX38450-B43X is available at Aetrix Electronics and suitable for portable sensor reference, low-power ADC biasing, IoT node power sequencing, and ESD-safe signal clamping requiring stable component supply with guaranteed long-term continuity.
Supply support for BZX38450-B43X 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 solutions with focus on efficiency, miniaturization, and automotive-grade reliability.
The BZX38450 series belongs to Nexperia's low-current Zener regulator portfolio, engineered specifically for precision voltage referencing in space- and power-constrained portable and battery-powered applications.
FAQ
What is the maximum continuous reverse power this diode can handle?
The BZX38450-B43X has a total power dissipation limit of 300 mW at ambient temperature ≤25 °C on standard FR4 PCB. This corresponds to a maximum continuous reverse current of approximately 7.0 mA at 43 V, assuming no additional thermal derating. Operation above this requires active cooling or reduced ambient temperature per the thermal resistance curve.
Can this Zener be used in forward conduction mode?
Yes - the BZX38450-B43X exhibits a forward voltage of 0.9 V at 10 mA, consistent with standard silicon diodes. It is routinely used in bidirectional ESD protection configurations where forward conduction handles positive transients and reverse breakdown clamps negative surges, provided series impedance limits peak current.
How does the ±2 % tolerance affect regulation accuracy over temperature?
The ±2 % tolerance applies at 25 °C and 50 µA; over −55 °C to +150 °C, the temperature coefficient is +0.05 mV/K, contributing <±1.2 V drift across the full range. Combined with initial tolerance, worst-case regulation spans 40.8 V to 45.2 V - verified in Table 9 for B-series devices under specified test conditions.
Is the SOD323 package compatible with standard reflow profiles?
Yes - the SOD323 package is qualified for lead-free reflow per J-STD-020. Recommended peak temperature is 260 °C for ≤30 seconds, with ramp rates ≤3 °C/s. Figure 10 provides the exact solder land pattern (0.5 mm pad width, 1.35 mm center-to-center pitch), and thermal resistance data confirms safe operation post-reflow without delamination or parameter shift.
BZX38450-B43X 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):
- 43 V
- Tolerance:
- ±2%
- Power - Max:
- 300 mW
- Impedance (Max) (Zzt):
- 150 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 32.6 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-B43X FAQ
1.How can I place an order for BZX38450-B43X through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX38450-B43X 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-B43X reliable?
The price and inventory of BZX38450-B43X are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX38450-B43X is usually 5 days.
3.What payment methods are accepted for BZX38450-B43X?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX38450-B43X transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX38450-B43X?
BZX38450-B43X orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX38450-B43X 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-B43X?
For technical support, including BZX38450-B43X datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX38450-B43X requirements.
6.How does Aetrix verify that BZX38450-B43X is sourced from the original manufacturer or authorized distributors?
All BZX38450-B43X 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-B43X meets industry standards.
7.What is the process for return or replacement of BZX38450-B43X?
All BZX38450-B43X units undergo pre-shipment inspection (PSI). If there is an issue with BZX38450-B43X, 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-B43X part is unused and in its original packaging.
Return procedure for BZX38450-B43X:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX38450-B43X 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
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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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