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Nexperia USA Inc. BZX38450-C43X
- Part No.:
- BZX38450-C43X
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-76, SOD-323
- Datasheet:
-
BZX38450-C43X.pdf
- Description:
- DIODE ZENER 43V 300MW SOD323
- Quantity:
- Payment:
- Shipping:
Inventory:6,335
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Product details
Overview
BZX38450-C43X from Nexperia is a low-current Zener voltage regulator diode in SOD323 (SC-76) package, rated for 43 V nominal working voltage at 50 µA test current, with ±5 % tolerance, 300 mW total power dissipation, and 375 Ω differential resistance at 2 mA. It serves as a precision reference or low-power voltage clamp in portable battery-powered circuits.
For engineers reviewing the BZX38450-C43X datasheet, BZX38450-C43X pinout, BZX38450-C43X application, or BZX38450-C43X equivalent, this page delivers verified electrical characteristics, thermal behavior, SOD323 terminal mapping, and validated alternative parts for low-bias regulation design.
Technical Context
This device operates as a reverse-biased Zener diode with specified breakdown at 43 V (min 40.85 V, max 45.15 V) under 50 µA test current, exhibiting a temperature coefficient of +0.05 mV/K and diode capacitance of 40 pF at 0 V. Its intentional minor leakage rise enables optimized fast switching and noise reduction per AN90031.
Designed for low-power biasing, it delivers stable regulation at ultra-low currents-ideal for sensor reference rails, microcontroller reset thresholds, and standby-mode voltage supervision where quiescent current must remain below 100 µA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Working Voltage (VZ) | 43 V nominal (40.85–45.15 V range at IZ = 50 µA); sets precise clamping level for low-current reference paths |
| Tolerance | ±5 % (C-series); enables cost-effective selection where tight regulation is secondary to low leakage and noise performance |
| Differential Resistance (rdiff) | 375 Ω at IZ = 2 mA; defines voltage deviation under small load variations in high-impedance bias networks |
| Power Dissipation (Ptot) | 300 mW at Tamb ≤ 25 °C on FR4 PCB; supports continuous operation in compact SMD layouts without forced cooling |
| Forward Voltage (VF) | ≤ 0.9 V at IF = 10 mA; ensures minimal drop when used in series-forward protection or dual-direction clamp configurations |
| Junction Temperature (Tj) | 150 °C maximum; allows reliable operation in industrial ambient environments up to +125 °C with proper PCB thermal relief |
| Thermal Resistance (Rth(j-a)) | 415 K/W in free air; informs derating curves for sustained power handling on standard single-sided copper PCBs |
Pinout & Package
SOD323 (SC-76) surface-mount plastic package: 1.7 mm × 1.25 mm × 0.95 mm body, 1.3 mm lead pitch, cathode marked by bar on top surface.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Cathode (K) | Connected to regulated output node; marking bar identifies this terminal for correct PCB orientation and polarity-sensitive placement |
| 2 | Anode (A) | Connected to ground or lower-potential rail; forms reverse-bias path enabling Zener conduction at VZ |
Key Features
| Feature | Design Value |
|---|---|
| Low test current operation | Specified at 50 µA-enables stable regulation in micropower systems where supply current is constrained to <100 µA |
| Optimized leakage profile | Intentional minor rise in reverse leakage per AN90031 improves transient response and reduces broadband noise in reference circuits |
| Small-footprint SMD package | SOD323 footprint fits high-density layouts; compatible with standard reflow and wave soldering per Figures 10–11 |
| Two tolerance options | C-series (±5 %) offers cost advantage over B-series (±2 %) while maintaining predictable regulation in non-critical bias applications |
Applications
| Portable Sensor Reference | Microcontroller Reset Circuit |
|---|---|
|
Use Scenario: Providing stable 43 V reference for analog front-end conditioning in battery-operated environmental sensors. IC Role / Device Role / Timing Role: Zener diode acting as precision shunt reference, sourcing <50 µA into high-impedance op-amp input stage. Use Value: Enables accurate ADC scaling without loading primary battery supply; 415 K/W Rth(j-a) prevents thermal drift during extended field deployment. |
Use Scenario: Generating clean, low-noise reset threshold for ARM Cortex-M0+ MCU in energy-harvesting nodes. IC Role / Device Role / Timing Role: Reverse-biased clamp defining VRESET trip point; leverages C-series leakage optimization for reduced digital noise coupling. Use Value: Eliminates need for external RC filter; 40 pF capacitance minimizes signal integrity impact on reset line edge rate. |
| Low-Power Voltage Monitor | Standby-Mode Rail Clamp |
|
Use Scenario: Supervising 48 V DC bus in IoT gateway during deep-sleep mode (<10 µA system current). IC Role / Device Role / Timing Role: Shunt regulator holding monitoring circuit at fixed 43 V, triggering supervisor IC when bus drops below threshold. Use Value: Draws only 50 µA at regulation-preserves battery life over years; ±5 % tolerance accommodates wide input variance without false triggers. |
Use Scenario: Clamping auxiliary 43 V bias rail in always-on subsystem of automotive telematics module. IC Role / Device Role / Timing Role: Transient suppressor and steady-state regulator, absorbing surge energy while maintaining reference stability. Use Value: Withstands 40 W non-repetitive peak reverse power (tp = 100 µs), preventing latch-up during load-dump events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX38450-B43 | ±2 % tolerance (vs. ±5 %), 350 Ω rdiff at 5 mA, identical VZ range and SOD323 package | Higher precision required for calibration references; tighter tolerance increases cost and limits availability in low-volume procurement | Select when absolute voltage accuracy >±2 % is mandatory and system budget permits premium tolerance grade |
| MMSZ43ET1G | 43 V nominal, ±5 %, 350 mW Ptot, SOD-123 package (2.7 mm × 1.6 mm), 500 Ω rdiff at 5 mA | Larger footprint and higher thermal resistance (500 K/W) reduce suitability for ultra-dense PCBs; higher Ptot does not compensate for inferior thermal performance | Choose only if SOD-123 is already standardized in legacy designs and board space is not constrained |
Compared with BZX38450-B43, the C43X trades voltage precision for lower cost and optimized leakage behavior; versus MMSZ43ET1G, it delivers superior thermal efficiency and smaller footprint-critical for next-gen portable electronics.
Availability
BZX38450-C43X is available at Aetrix Electronics and suitable for portable sensor reference, microcontroller reset circuit, and low-power voltage monitor applications requiring stable component supply across production lifecycles.
Supply support for BZX38450-C43X 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 leading semiconductor manufacturer specializing in high-performance, energy-efficient logic, discrete, and MOSFET devices for automotive, industrial, and consumer markets.
The BZX38450 series belongs to Nexperia's low-current Zener regulator portfolio, engineered specifically for battery-powered and ultra-low-power applications where minimal test current and controlled leakage are essential design requirements.
FAQ
What is the maximum reverse current (IR) specification for BZX38450-C43X at 40 V?
At VR = 40 V and Tamb = 25 °C, the typical reverse current is 0.05 µA, with no maximum limit specified in the datasheet-consistent with its C-series design intent for ultra-low leakage operation. This value is confirmed in Table 9 for all C-series parts from BZX38450-C39 onward.
Can BZX38450-C43X be used in series with another Zener to achieve higher regulation voltage?
No-BZX38450-C43X is not characterized for series operation. Its differential resistance (375 Ω) and thermal coefficient (+0.05 mV/K) are specified individually; cascading introduces unpredictable voltage division, mismatched temperature drift, and potential thermal runaway due to unequal power sharing.
Does the "minor rise of leakage current" in C-series devices affect long-term reliability?
No adverse reliability impact is documented. The controlled leakage increase is a deliberate design feature per AN90031 to improve switching speed and noise performance; accelerated life testing confirms full compliance with Nexperia's 150 °C junction temperature rating and 1000-hour HTOL requirements.
Is the SOD323 footprint compatible with automated optical inspection (AOI) systems?
Yes-the 1.7 mm × 1.25 mm body with visible cathode bar marking meets IPC-A-610 Class 2/3 solder joint inspection criteria. Standard AOI algorithms reliably detect tombstoning, skew, and solder bridging using the defined solder land dimensions in Figure 10 (reflow) and Figure 11 (wave).
BZX38450-C43X Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- -
- Package/Case:
- SC-76, SOD-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Voltage - Zener (Nom) (Vz):
- 43 V
- Tolerance:
- ±5%
- 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-C43X FAQ
1.How can I place an order for BZX38450-C43X through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX38450-C43X 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-C43X reliable?
The price and inventory of BZX38450-C43X are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX38450-C43X is usually 5 days.
3.What payment methods are accepted for BZX38450-C43X?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX38450-C43X transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX38450-C43X?
BZX38450-C43X orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX38450-C43X 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-C43X?
For technical support, including BZX38450-C43X datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX38450-C43X requirements.
6.How does Aetrix verify that BZX38450-C43X is sourced from the original manufacturer or authorized distributors?
All BZX38450-C43X 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-C43X meets industry standards.
7.What is the process for return or replacement of BZX38450-C43X?
All BZX38450-C43X units undergo pre-shipment inspection (PSI). If there is an issue with BZX38450-C43X, 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-C43X part is unused and in its original packaging.
Return procedure for BZX38450-C43X:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX38450-C43X Tags
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BZT52C5V6T-7
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MMSZ5231B-7-F
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MM5Z5V1ST1G
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