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Nexperia USA Inc. BZX84W-B43X
- Part No.:
- BZX84W-B43X
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-70, SOT-323
- Datasheet:
-
BZX84W-B43X.pdf
- Description:
- DIODE ZENER 43V 275MW SOT323
- Quantity:
- Payment:
- Shipping:
Inventory:5,344
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Product details
Overview
BZX84W-B43X from Nexperia is a ±2% tolerance Zener voltage regulator diode in SOT323 (SC-70) package, rated for 43 V nominal Zener voltage at 2 mA test current, 275 mW total power dissipation, and 150 °C maximum junction temperature. It serves as a precision reference or overvoltage clamp in low-power analog supply rails and signal conditioning circuits.
For engineers reviewing the BZX84W-B43X datasheet, BZX84W-B43X pinout, BZX84W-B43X application, or BZX84W-B43X equivalent, this page delivers verified electrical parameters, thermal behavior, SOT323 terminal mapping, and real-world use cases for stable voltage regulation in compact PCB designs.
Technical Context
This Zener diode operates in reverse breakdown with a typical differential resistance of 375 Ω at 2 mA and exhibits a positive temperature coefficient of +41.2 mV/K, enabling predictable drift compensation in bias networks. Its non-repetitive peak reverse power dissipation reaches 40 W for 100 µs pulses, supporting transient suppression in low-energy surge events.
Designed for surface-mount reflow assembly on FR4 PCBs with single-sided copper, it achieves a junction-to-ambient thermal resistance of 455 K/W under standard footprint conditions and maintains leakage current ≤50 nA at 0.7 × VZnom, ensuring low quiescent error in reference paths.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 42.1 V to 43.9 V at IZ = 2 mA - defines precise clamping threshold for 43 V nominal regulation |
| Tolerance | ±2% (B-series) - enables tight supply rail margining without post-calibration |
| Differential Resistance (rdif) | 375 Ω max at IZ = 2 mA - determines output impedance and load regulation error |
| Temperature Coefficient (SZ) | +41.2 mV/K - quantifies voltage drift per degree Celsius rise in junction temperature |
| Total Power Dissipation (Ptot) | 275 mW at Tamb = 25 °C on FR4 - sets continuous DC power limit for thermal design |
| Reverse Leakage (IR) | ≤50 nA at VR = 0.7 × VZnom - ensures minimal current draw in standby reference nodes |
| Forward Voltage (VF) | ≤0.9 V at IF = 10 mA - supports bidirectional protection or forward-biased bypass functions |
Pinout & Package
SOT323 (SC-70) plastic surface-mounted package with 3 leads; leadless construction optimized for high-density PCB layouts and automated reflow assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode (A) | Forward-biased terminal; connects to lower-potential node in Zener operation |
| 2 | Not Connected (n.c.) | Internally unconnected; must remain floating-no PCB trace or solder joint |
| 3 | Cathode (K) | Reverse-biased terminal; connects to higher-potential node for Zener breakdown conduction |
Key Features
| Feature | Design Value |
|---|---|
| ±2% Zener voltage tolerance | Reduces need for external trimming in 43 V reference designs, improving yield in production calibration |
| 275 mW power rating on FR4 | Supports sustained regulation in space-constrained consumer and industrial modules without heatsinking |
| Low 50 nA leakage at 0.7×VZ | Minimizes error current in high-impedance feedback or sensing nodes, preserving accuracy |
| SOT323 footprint compatibility | Enables drop-in replacement in legacy SC-70 designs and leverages existing pick-and-place tooling |
| +41.2 mV/K temperature coefficient | Allows predictable thermal drift modeling for compensated voltage references across −55 °C to +150 °C |
Applications
| Power Supply Reference | Overvoltage Clamp |
|---|---|
Use Scenario: Stabilizing 43 V auxiliary rail in isolated DC-DC converter feedback loop. IC Role / Device Role / Timing Role: Zener diode provides fixed reference voltage for optocoupler-based error amplification. Use Value: ±2% tolerance ensures <1% output voltage deviation across unit-to-unit variation without trim potentiometers. |
Use Scenario: Protecting microcontroller GPIO input against accidental 48 V bus exposure. IC Role / Device Role / Timing Role: Reverse-biased Zener shunts excess voltage above 43 V to ground during transients. Use Value: 40 W non-repetitive peak power handling absorbs 100 µs surges without degradation. |
| Signal Level Shifting | Current Source Biasing |
Use Scenario: Translating 0–5 V sensor output to 38–43 V range for high-side current monitor interface. IC Role / Device Role / Timing Role: Anode tied to 5 V source; cathode referenced to 43 V rail establishes offset voltage. Use Value: Low 375 Ω dynamic resistance maintains linearity within ±0.5% over 100 µA–1 mA signal swing. |
Use Scenario: Setting bias point for high-voltage op-amp stage operating near 43 V supply. IC Role / Device Role / Timing Role: Zener regulates current through series resistor to establish stable tail current. Use Value: +41.2 mV/K TC allows matching with transistor VBE drift to minimize temperature-induced offset. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84W-C43 | ±5% tolerance (40.0–46.0 V range), higher leakage (≤100 nA), same SOT323 package | Acceptable where cost sensitivity outweighs precision; less suitable for closed-loop feedback | Select when budget constraints dominate and ±5% regulation error is acceptable in final system spec |
| MMSZ43ET1G | ±5% tolerance, 500 mW Ptot, SOD-123 package, 300 Ω rdif at 5 mA | Higher power capability but larger footprint; requires layout revision and thermal reassessment | Choose only if >275 mW continuous dissipation is required and board area permits SOD-123 rework |
Compared with BZX84W-C43, the BZX84W-B43X offers tighter voltage control critical for feedback accuracy; versus MMSZ43ET1G, it trades power headroom for miniaturization and thermal compatibility with dense SOT323 layouts.
Availability
BZX84W-B43X is available at Aetrix Electronics and suitable for power supply reference, overvoltage clamp, and signal level shifting applications requiring stable component supply, consistent parametric performance, and long-term obsolescence management.
Supply support for BZX84W-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 focused on high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified and industrial-grade components.
The BZX84W series belongs to Nexperia's general-purpose Zener diode product line, engineered for precision voltage regulation and transient suppression in space-constrained, cost-sensitive consumer and industrial electronics.
FAQ
What is the maximum continuous reverse current for BZX84W-B43X at 25 °C ambient?
The device has no specified maximum continuous reverse current; instead, its safe operating limit is defined by total power dissipation. At 25 °C ambient on FR4 PCB, it sustains up to 275 mW, corresponding to ~6.4 mA average reverse current (275 mW ÷ 43 V). Exceeding this risks thermal runaway due to positive temperature coefficient.
Can BZX84W-B43X be used in parallel for higher power handling?
No-parallel connection is not recommended. The +41.2 mV/K temperature coefficient causes thermal runaway: as one diode heats, its Zener voltage rises, diverting more current to the cooler unit until failure. For higher power, select a single higher-rated Zener or implement active current sharing.
Is the n.c. pin (pin 2) electrically isolated or internally bonded?
Pin 2 is internally not connected-no die bond wire or metallization links it to the silicon. It must remain unconnected on the PCB; soldering or routing to any net violates the absolute maximum ratings and may cause mechanical stress or shorting during thermal cycling.
How does the 455 K/W junction-to-ambient thermal resistance impact PCB layout?
This value assumes a standard SOT323 footprint on single-sided FR4 with tin-plated copper. To maintain Tj ≤150 °C at full 275 mW, ambient must stay ≤85 °C. Layout improvements-such as adding thermal vias under the pad or using double-sided copper-can reduce effective Rth(j-a) but require revalidation per Nexperia's AN10312 guidelines.
BZX84W-B43X Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- BZX84W
- Package/Case:
- SC-70, SOT-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 43 V
- Tolerance:
- ±2%
- Power - Max:
- 275 mW
- Impedance (Max) (Zzt):
- 150 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 30.1 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-323
BZX84W-B43X FAQ
1.How can I place an order for BZX84W-B43X through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84W-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 BZX84W-B43X reliable?
The price and inventory of BZX84W-B43X are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX84W-B43X is usually 5 days.
3.What payment methods are accepted for BZX84W-B43X?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84W-B43X transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84W-B43X?
BZX84W-B43X orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84W-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 BZX84W-B43X?
For technical support, including BZX84W-B43X datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84W-B43X requirements.
6.How does Aetrix verify that BZX84W-B43X is sourced from the original manufacturer or authorized distributors?
All BZX84W-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 BZX84W-B43X meets industry standards.
7.What is the process for return or replacement of BZX84W-B43X?
All BZX84W-B43X units undergo pre-shipment inspection (PSI). If there is an issue with BZX84W-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 BZX84W-B43X part is unused and in its original packaging.
Return procedure for BZX84W-B43X:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84W-B43X Tags
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MMBZ5240B-7-F
Diodes Incorporated
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Diodes Incorporated
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MMSZ5231B-7-F
Diodes Incorporated
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Diodes Incorporated
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BZX84C3V3LT1G
onsemi
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MMSZ5245BS-7-F
Diodes Incorporated
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MM5Z5V1ST1G
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SMAJ4744A-TP
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SMAZ12-13-F
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