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Nexperia USA Inc. BZX84W-C3V9X
- Part No.:
- BZX84W-C3V9X
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-70, SOT-323
- Datasheet:
-
BZX84W-C3V9X.pdf
- Description:
- DIODE ZENER 3.9V 275MW SOT323
- Quantity:
- Payment:
- Shipping:
Inventory:3,000
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Product details
Overview
BZX84W-C3V9X from Nexperia is a ±5 % tolerance Zener voltage regulator diode in SOT323 (SC-70) package, rated for 3.9 V nominal Zener voltage at 5 mA, 275 mW total power dissipation, and 3 µA reverse current at 1 V, used for precision low-power voltage reference and overvoltage protection in compact DC power rails.
For engineers reviewing the BZX84W-C3V9X datasheet, BZX84W-C3V9X pinout, BZX84W-C3V9X application, or BZX84W-C3V9X equivalent, this page delivers verified Zener parameters, thermal resistance (455 K/W), differential resistance (90 Ω), temperature coefficient (−2.5 mV/K), and SC-70 terminal mapping to support stable biasing and regulation design in space-constrained layouts.
Technical Context
This Zener diode operates in reverse breakdown with tightly controlled VZ = 3.70–4.10 V at IZ = 5 mA, exhibiting low dynamic impedance (90 Ω typical) and negative temperature coefficient (−2.5 mV/K) ideal for temperature-stable reference generation. Its 3 µA leakage at 1 V enables low-quiescent-current regulation.
The device uses silicon planar technology in a leadless SOT323 package with anode (Pin 1), not-connected (Pin 2), and cathode (Pin 3) terminals, optimized for high-frequency stability up to 1 MHz (Cd = 6 pF) and reflow-compatible mounting on FR4 PCBs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 3.70–4.10 V at IZ = 5 mA; defines precise regulation threshold for 3.3 V rail clamping or biasing |
| Tolerance | ±5 % ('C' grade); ensures predictable voltage margin for non-critical reference applications |
| Differential Resistance (rdiff) | 90 Ω max at IZ = 5 mA; limits output voltage shift under load current variation |
| Reverse Current (IR) | 3 µA max at VR = 1 V; enables low-leakage standby operation in battery-powered circuits |
| Total Power Dissipation (Ptot) | 275 mW at Tamb = 25 °C on FR4; sets maximum continuous Zener current to ~70 mA |
| Thermal Resistance (Rth(j-a)) | 455 K/W; determines junction temperature rise (~125 °C at full Ptot) on standard PCB |
| Capacitance (Cd) | 6 pF at f = 1 MHz, VR = 0 V; supports stable performance in noise-sensitive analog feedback paths |
Pinout & Package
SOT323 (SC-70) surface-mount plastic package: 1.35 mm × 1.75 mm footprint, 0.95 mm height, leadless construction with tin-plated terminations compatible with standard reflow profiles.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode (A) | Connected to lower-potential side of regulated node; forward-biased during transient surges |
| 2 | Not Connected (n.c.) | Internally unconnected; no PCB trace or solder pad required; must remain floating |
| 3 | Cathode (K) | Connected to higher-potential side (e.g., VIN); reverse-biased during regulation |
Key Features
| Feature | Design Value |
|---|---|
| Wide Zener voltage range | 2.4–75 V in E24 steps enables single-family coverage across most low-voltage regulation needs |
| Low dynamic impedance | 90 Ω max ensures minimal output voltage deviation under ±1 mA load changes |
| Negative temperature coefficient | −2.5 mV/K compensates for positive TC of other components in mixed-signal references |
| High-frequency stability | 6 pF capacitance supports clean regulation in switching supply feedback loops up to 1 MHz |
| Reflow-optimized footprint | Standard SOT323 land pattern (2.65 × 2.35 mm) ensures manufacturable assembly without tombstoning |
Applications
| Power Supply Rail Clamping | Low-Power Reference Generation |
|---|---|
|
Use Scenario: Protecting 3.3 V microcontroller I/O pins from transient overvoltage during hot-plug or ESD events. IC Role / Device Role / Timing Role: Zener clamp placed between I/O line and ground, conducting above 3.9 V to shunt surge current. Use Value: 3 µA leakage preserves signal integrity during normal operation; 275 mW rating handles 100 µs surges up to 40 W peak. |
Use Scenario: Providing stable 3.9 V bias for op-amp comparators in battery-operated sensor nodes. IC Role / Device Role / Timing Role: Reverse-biased Zener supplying fixed reference voltage to comparator input via current-limiting resistor. Use Value: −2.5 mV/K TC minimizes drift over −40 to +85 °C; 90 Ω rdiff maintains <10 mV error under 100 µA load variation. |
| DC-DC Feedback Divider | Signal Level Translation |
|
Use Scenario: Setting output voltage of adjustable buck converter by replacing top resistor in feedback divider with Zener. IC Role / Device Role / Timing Role: Zener replaces R1 in standard resistive divider, establishing fixed VREF at FB pin independent of input ripple. Use Value: 6 pF capacitance avoids phase lag in control loop; 275 mW rating allows use with >10 kΩ divider impedances without thermal derating. |
Use Scenario: Shifting logic-level signals from 5 V MCU to 3.3 V peripheral while limiting voltage excursion. IC Role / Device Role / Timing Role: Anode grounded, cathode tied to signal line; conducts only when signal exceeds 3.9 V + 0.9 V forward drop. Use Value: 0.9 V forward voltage enables bidirectional clamping; SOT323 size fits dense routing near FPGA I/O banks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ON Semiconductor MMBZ5226BS-7-F | 3.9 V, ±5 %, 200 mW, SOT-23 package, 10 µA IR at 1 V | Higher leakage and lower Ptot limit continuous current to ~50 mA | Select when legacy SOT-23 footprint compatibility is required over SC-70 miniaturization |
| Vishay BZX84-C3V9-TP | 3.9 V, ±5 %, 300 mW, SOT-23, 3 µA IR, 100 Ω rdiff | 25 mW higher power rating but 10 Ω higher impedance degrades regulation accuracy | Prefer for higher-power clamping where 0.1 V extra dropout is acceptable |
Compared with BZX84W-C3V9X, the MMBZ5226BS-7-F trades 75 mW power headroom and 7 µA extra leakage for SOT-23 compatibility, while the BZX84-C3V9-TP offers greater surge capacity at the cost of reduced regulation precision due to higher dynamic impedance.
Availability
BZX84W-C3V9X is available at Aetrix Electronics and suitable for power supply rail clamping, low-power reference generation, DC-DC feedback divider stabilization, and signal level translation requiring stable component supply across industrial control, IoT sensor modules, and consumer electronics production.
Supply support for BZX84W-C3V9X 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 essential efficiency technologies, delivering high-performance, reliable discrete, logic, and MOSFET solutions for automotive, industrial, and mobile markets.
The BZX84W series belongs to Nexperia's general-purpose Zener diode product line, engineered for compact, high-reliability voltage regulation in space-constrained SMD applications with emphasis on thermal stability and manufacturing robustness.
FAQ
What is the maximum continuous Zener current for BZX84W-C3V9X at 25 °C ambient?
The maximum continuous Zener current is calculated from Ptot = 275 mW and VZ = 3.9 V, yielding IZ(max) ≈ 70.5 mA. Derating is required above 25 °C per the 455 K/W thermal resistance; at 70 °C ambient, usable current drops to ~45 mA to maintain Tj ≤ 150 °C.
Can BZX84W-C3V9X replace a 3.3 V Zener in a 3.3 V rail clamp?
No - BZX84W-C3V9X has a nominal Zener voltage of 3.9 V (3.70–4.10 V range), exceeding the 3.3 V rail by 0.6–0.8 V. For 3.3 V clamping, BZX84W-C3V3X (3.10–3.50 V) is the correct variant; using C3V9X would allow rail voltage to rise to ~3.9 V before conduction begins.
Why does Pin 2 show 'n.c.' and how should it be handled on the PCB?
Pin 2 is internally not connected and serves only as a mechanical alignment aid in the SOT323 mold. It must remain unconnected on the PCB - no copper trace, solder mask opening, or thermal relief should be assigned. Including it in the footprint risks solder bridging or mechanical stress during reflow.
How does the −2.5 mV/K temperature coefficient affect long-term reference stability?
A −2.5 mV/K coefficient means VZ decreases by 2.5 mV per Kelvin rise in junction temperature. Over a 100 K range (−40 to +60 °C ambient, assuming ΔTj-a ≈ ΔTamb), VZ shifts by ~250 mV - a 6.4 % change. For high-stability references, this requires compensation or operation within narrow ambient bands.
BZX84W-C3V9X 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):
- 3.9 V
- Tolerance:
- ±5%
- Power - Max:
- 275 mW
- Impedance (Max) (Zzt):
- 90 Ohms
- Current - Reverse Leakage @ Vr:
- 3 µA @ 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-C3V9X FAQ
1.How can I place an order for BZX84W-C3V9X through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84W-C3V9X 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-C3V9X reliable?
The price and inventory of BZX84W-C3V9X are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX84W-C3V9X is usually 5 days.
3.What payment methods are accepted for BZX84W-C3V9X?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84W-C3V9X transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84W-C3V9X?
BZX84W-C3V9X orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84W-C3V9X 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-C3V9X?
For technical support, including BZX84W-C3V9X datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84W-C3V9X requirements.
6.How does Aetrix verify that BZX84W-C3V9X is sourced from the original manufacturer or authorized distributors?
All BZX84W-C3V9X 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-C3V9X meets industry standards.
7.What is the process for return or replacement of BZX84W-C3V9X?
All BZX84W-C3V9X units undergo pre-shipment inspection (PSI). If there is an issue with BZX84W-C3V9X, 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-C3V9X part is unused and in its original packaging.
Return procedure for BZX84W-C3V9X:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84W-C3V9X Tags
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