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Nexperia USA Inc. BZX84W-B51-QX
- Part No.:
- BZX84W-B51-QX
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-70, SOT-323
- Datasheet:
-
BZX84W-B51-QX.pdf
- Description:
- DIODE ZENER 51V 275MW SOT323
- Quantity:
- Payment:
- Shipping:
Inventory:5,106
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Product details
Overview
BZX84W-B51-QX from Nexperia is a ±2% tolerance Zener diode in SOT323 (SC-70) package, rated for 51 V nominal regulation voltage, 275 mW total power dissipation at 25 °C, and qualified to AEC-Q101 for automotive use. It provides precise voltage reference and overvoltage protection in compact power management circuits.
For engineers reviewing the BZX84W-B51-QX datasheet, BZX84W-B51-QX pinout, BZX84W-B51-QX application, or BZX84W-B51-QX equivalent, this page delivers verified Zener parameters including VZ = 50.0–52.0 V, IZ = 5 mA test condition, rdif = 400 Ω max, temperature coefficient of +51.0 mV/K, and reverse leakage IR ≤ 200 nA at VR = 35.7 V.
Technical Context
This Zener operates in reverse breakdown with a nominal 51 V regulation voltage at IZ = 5 mA, exhibiting a positive temperature coefficient of +51.0 mV/K - indicating stable voltage drift across temperature in mid-range Zener voltages. Its differential resistance is capped at 400 Ω under 5 mA bias, supporting low-noise reference stability.
The device uses a planar epitaxial process in a leadless SOT323 package, enabling high thermal resistance (Rth(j-a) = 455 K/W on FR4), and features a non-connected (n.c.) terminal (Pin 2) to support layout flexibility while maintaining anode/cathode isolation per JEDEC SC-70 footprint.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 50.0 V to 52.0 V at IZ = 5 mA - defines tight ±2% regulation window for precision reference applications |
| Differential Resistance rdif | ≤ 400 Ω at IZ = 5 mA - ensures minimal output impedance and low dynamic voltage deviation under load transients |
| Temperature Coefficient SZ | +51.0 mV/K at IZ = 5 mA - indicates predictable, linear positive VZ drift with junction temperature rise |
| Reverse Leakage IR | ≤ 200 nA at VR = 35.7 V (0.7 × VZnom) - guarantees ultra-low standby current in battery-sensitive circuits |
| Total Power Dissipation Ptot | 275 mW at Tamb = 25 °C on FR4 PCB - sets maximum continuous DC power handling under standard mounting conditions |
| Forward Voltage VF | ≤ 0.9 V at IF = 10 mA - enables low-loss forward conduction when used in bidirectional clamping or polarity protection |
| Junction Temperature Tj | −55 °C to +150 °C - supports operation in under-hood automotive environments and industrial control enclosures |
Pinout & Package
SOT323 (SC-70) plastic surface-mounted package: 1.7 mm × 1.25 mm × 0.95 mm body, leadless, three-terminal, single-sided copper FR4 mountable.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode (A) | Forward current entry point; reverse-biased connection to ground or low-impedance node during regulation |
| 2 | Not Connected (n.c.) | Internally isolated metal pad - no electrical function; allows routing clearance without short risk |
| 3 | Cathode (K) | Regulated output node; connected to supply rail or feedback path where stable 51 V reference is required |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive-grade reliability including HTOL, temperature cycling, and ESD robustness per JESD22 standards |
| ±2% Zener voltage tolerance | Enables tighter system-level voltage margining than ±5% variants, reducing need for post-regulation trimming |
| Low 200 nA leakage at 35.7 V | Minimizes quiescent current draw in always-on automotive modules such as CAN wake-up receivers or sensor bias networks |
| 455 K/W thermal resistance | Allows direct PCB thermal design using standard FR4 without heatsinking for <100 mW average dissipation |
| Non-repetitive peak power: 40 W | Supports transient surge suppression up to 100 µs pulses, e.g., ISO 7637-2 Load Dump spike clamping |
Applications
| Automotive Body Control Module (BCM) | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Voltage reference for microcontroller ADC input scaling in door module ECUs exposed to 12 V battery fluctuations. IC Role / Device Role / Timing Role: Zener diode providing stable 51 V reference for internal LDO feedback divider or external analog front-end calibration. Use Value: Maintains <±0.5% reference accuracy across −40 °C to +125 °C ambient due to +51.0 mV/K coefficient and AEC-Q101 thermal cycling validation. |
Use Scenario: Overvoltage clamp protecting 24 V industrial current-loop transmitter inputs from field wiring surges. IC Role / Device Role / Timing Role: Reverse-biased Zener shunting transients above 51 V to ground, limiting input stage stress during EFT bursts. Use Value: Withstands 40 W non-repetitive peaks (100 µs) and exhibits only 200 nA leakage at 35.7 V, preserving loop integrity during normal operation. |
| Automotive Infotainment Power Sequencing | Medical Diagnostic Equipment Reference |
Use Scenario: Biasing circuit for high-side PMOS enable logic requiring precise 51 V gate threshold detection in head unit power tree. IC Role / Device Role / Timing Role: Zener-based comparator reference ensuring accurate sequencing timing between 5 V, 3.3 V, and 1.8 V rails. Use Value: Tight ±2% VZ tolerance eliminates need for external trimming resistors, reducing BOM count and board space in space-constrained infotainment modules. |
Use Scenario: Precision voltage reference for photodiode amplifier offset nulling in portable ultrasound probe front-ends. IC Role / Device Role / Timing Role: Stable 51 V Zener supplying bias to op-amp compensation network requiring sub-10 ppm/°C drift contribution. Use Value: +51.0 mV/K coefficient is fully characterized and compensated in system calibration, enabling <0.02% full-scale error over operating temperature range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84W-C51-Q | ±5% tolerance (48.0–54.0 V); identical package, power rating, and AEC-Q101 qualification | Acceptable where system-level voltage margin allows wider regulation band; lower cost tier | Select for cost-sensitive automotive modules where 51 V reference does not drive critical ADC or timing circuits |
| MMSZ5257B-TP | ±5% tolerance (48.45–53.55 V); SOD-123 package; 500 mW Ptot; not AEC-Q101 qualified | Higher power handling but larger footprint; unsuitable for under-hood automotive deployment | Choose only for industrial or consumer applications needing >275 mW dissipation and where AEC compliance is not required |
Compared with BZX84W-C51-Q, the BZX84W-B51-QX offers tighter regulation for precision analog functions; compared with MMSZ5257B-TP, it trades higher power for automotive qualification and smaller SOT323 size - making it optimal for space-constrained, safety-critical vehicle subsystems.
Availability
BZX84W-B51-QX is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor interfaces, and medical diagnostic equipment requiring stable component supply with guaranteed AEC-Q101 compliance and traceable lot history.
Supply support for BZX84W-B51-QX 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 efficiency-driven, high-volume discrete and logic devices, with leadership in automotive-qualified components and advanced packaging.
The BZX84W-Q series belongs to Nexperia's automotive Zener portfolio, designed specifically for reliable voltage regulation and transient suppression in harsh-environment electronic control units.
FAQ
What is the exact Zener voltage range for BZX84W-B51-QX at 5 mA test current?
The BZX84W-B51-QX has a guaranteed Zener voltage range of 50.0 V to 52.0 V when measured at IZ = 5 mA and Tj = 25 °C, reflecting its ±2% tolerance specification per the official Nexperia datasheet Rev. 1 (2021). This range is validated across production lots and forms the basis for all downstream voltage reference design calculations.
Is Pin 2 electrically functional or a mechanical dummy pad?
Pin 2 is explicitly designated "n.c." (not connected) in the Nexperia datasheet pinning table and schematic symbol. It is an isolated metal land with no internal semiconductor connection - serving solely as a mechanical anchor and routing relief in the SOT323 footprint. No current, voltage, or signal should be applied to this terminal.
Can BZX84W-B51-QX replace BZX84W-C51-Q in an existing design?
Yes, BZX84W-B51-QX is a direct drop-in replacement for BZX84W-C51-Q in terms of package, pinout, power rating, and thermal behavior - the only difference is tighter ±2% voltage tolerance (vs. ±5%). No layout or schematic changes are needed; however, system-level voltage margin analysis should confirm that the narrower 50.0–52.0 V band improves, rather than constrains, performance.
What is the maximum non-repetitive surge current the device can handle?
At Tamb = 25 °C, the BZX84W-B51-QX supports a non-repetitive peak reverse current IZSM of 0.78 A for 100 µs pulses, derived from its 40 W peak power rating (PZSM = VZ × IZSM). This capability is validated per IEC 60134 limiting values and is used in automotive load-dump and EFT transient protection designs.
BZX84W-B51-QX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- BZX84W-Q
- Package/Case:
- SC-70, SOT-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 51 V
- Tolerance:
- ±1.96%
- Power - Max:
- 275 mW
- Impedance (Max) (Zzt):
- 180 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 35.7 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-323
BZX84W-B51-QX FAQ
1.How can I place an order for BZX84W-B51-QX through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84W-B51-QX 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-B51-QX reliable?
The price and inventory of BZX84W-B51-QX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX84W-B51-QX is usually 5 days.
3.What payment methods are accepted for BZX84W-B51-QX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84W-B51-QX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84W-B51-QX?
BZX84W-B51-QX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84W-B51-QX 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-B51-QX?
For technical support, including BZX84W-B51-QX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84W-B51-QX requirements.
6.How does Aetrix verify that BZX84W-B51-QX is sourced from the original manufacturer or authorized distributors?
All BZX84W-B51-QX 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-B51-QX meets industry standards.
7.What is the process for return or replacement of BZX84W-B51-QX?
All BZX84W-B51-QX units undergo pre-shipment inspection (PSI). If there is an issue with BZX84W-B51-QX, 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-B51-QX part is unused and in its original packaging.
Return procedure for BZX84W-B51-QX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84W-B51-QX Tags
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MM5Z5V1ST1G
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