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Nexperia USA Inc. BZX384-A51-QX
- Part No.:
- BZX384-A51-QX
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-76, SOD-323
- Datasheet:
-
BZX384-A51-QX.pdf
- Description:
- DIODE ZENER 51V 300MW SOD323
- Quantity:
- Payment:
- Shipping:
Inventory:2,765
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Product details
Overview
BZX384-A51-QX from Nexperia is a ±1 % tolerance Zener voltage regulator diode in SOD323 (SC-76) package, rated for 51 V nominal breakdown voltage at 5 mA, 300 mW total power dissipation, and qualified to AEC-Q101 for automotive voltage reference and overvoltage protection circuits.
For engineers reviewing the BZX384-A51-QX datasheet, BZX384-A51-QX pinout, BZX384-A51-QX application, or BZX384-A51-QX equivalent, key selection factors include its tight ±1 % VZ tolerance, low 400 Ω differential resistance at IZ = 5 mA, 0.4 μA reverse current at VR = 38.8 V, and thermal resistance of 110 K/W from junction to solder point - critical for stable biasing in space-constrained automotive ECUs and sensor interfaces.
Technical Context
This Zener diode operates in reverse breakdown mode to maintain a stable reference voltage under varying load and temperature conditions. Its 51 V nominal Zener voltage is specified at 5 mA test current with ±1 % initial tolerance and a temperature coefficient of +12.6 mV/K at IZ = 5 mA.
The device features non-repetitive peak reverse power dissipation of 40 W (100 μs pulse), junction-to-ambient thermal resistance of 415 K/W on FR4 PCB, and junction-to-solder-point thermal resistance of 110 K/W - enabling reliable transient suppression and precision regulation in thermally constrained layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 50.49 V to 51.51 V at IZ = 5 mA - ensures precise 51 V reference with ±1 % accuracy for feedback loops and voltage monitoring. |
| Differential Resistance (rdif) | 400 Ω max at IZ = 5 mA - low dynamic impedance maintains regulation stability against load current variations. |
| Reverse Current (IR) | 0.4 μA max at VR = 38.8 V - minimal leakage preserves accuracy in high-impedance sensing nodes. |
| Total Power Dissipation (Ptot) | 300 mW at Tamb ≤ 25 °C - defines continuous DC power handling on standard FR4 PCB with single-sided copper. |
| Non-repetitive Peak Power (PZSM) | 40 W for tp = 100 μs - supports surge immunity in automotive load-dump and ESD protection paths. |
| Junction Temperature (Tj) | −65 °C to +150 °C - enables operation in under-hood automotive environments without derating. |
| AEC-Q101 Qualified | Qualified per Automotive Electronics Council stress test standard - validated for use in automotive powertrain and body control modules. |
Pinout & Package
Package: SOD323 (SC-76), surface-mount plastic package with 2 leads, 2.3 mm × 1.35 mm footprint, cathode marked by bar on top surface.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Cathode (K) | Connected to regulated output node; polarity must be observed for correct Zener conduction in reverse bias. |
| 2 | Anode (A) | Connected to ground or lower-potential rail; forms reference return path during regulation. |
Key Features
| Feature | Design Value |
|---|---|
| ±1 % Zener voltage tolerance | Enables high-accuracy voltage references without external trimming in automotive sensor signal conditioning. |
| AEC-Q101 qualification | Validated for automotive-grade reliability including HTOL, temperature cycling, and HAST - suitable for engine control units. |
| Low 400 Ω differential resistance | Minimizes output voltage deviation under ±1 mA load current changes - critical for stable ADC reference buffers. |
| SOD323 compact footprint | 0.8 mm height and 2.3 mm × 1.35 mm area allow placement near IC pins for localized decoupling and noise reduction. |
| 40 W non-repetitive surge rating | Withstands ISO 7637-2 Pulse 1/2a/5a transients without degradation - simplifies front-end protection design. |
Applications
| Automotive Engine Control Unit (ECU) | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Providing stable 51 V reference for knock sensor biasing and fuel injector driver feedback networks. IC Role / Device Role / Timing Role: Zener voltage reference diode establishing precise threshold for analog comparators and ADC input scaling. Use Value: ±1 % VZ tolerance and +12.6 mV/K temperature coefficient ensure <±2 % total drift over −40 °C to +125 °C ambient range. |
Use Scenario: Regulating excitation voltage for 4–20 mA loop-powered pressure transmitters operating from 48 V supply rails. IC Role / Device Role / Timing Role: Shunt regulator maintaining constant bias across bridge sensors and instrumentation amplifiers. Use Value: 400 Ω rdif limits output variation to <20 mV under 50 μA load shifts - preserving measurement linearity. |
| Automotive Body Control Module (BCM) | Power Supply Overvoltage Protection |
Use Scenario: Clamping LIN bus transceiver supply rail during load dump events in door module electronics. IC Role / Device Role / Timing Role: Transient voltage suppressor absorbing short-duration surges while maintaining steady-state regulation. Use Value: 40 W PZSM rating handles 100 μs pulses up to 40 V above nominal - meeting ISO 16750-2 requirements. |
Use Scenario: Secondary overvoltage clamp in 48 V DC-DC converter output stage to protect downstream FET gates. IC Role / Device Role / Timing Role: Precision shunt limiter activating at 51 V to divert excess current before MOSFET breakdown. Use Value: 0.4 μA IR at 38.8 V ensures negligible quiescent loss during normal operation below trip threshold. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX384-B51-Q | ±2 % VZ tolerance (50.0 V–52.0 V), higher 600 Ω rdif, same SOD323 package | Acceptable where ±2 % reference accuracy suffices, e.g., non-critical power rail monitoring | Select when cost sensitivity outweighs need for ±1 % precision; identical footprint and thermal performance. |
| MMSZ5257B-TP | ±5 % VZ (48.45 V–53.55 V), 600 mW Ptot, SOD-123 package (larger, 2.7 mm × 1.6 mm) | Higher power handling but looser tolerance and larger board area - suited for industrial power supplies | Choose only if 600 mW dissipation is required and board space permits larger SOD-123; not AEC-Q101 qualified. |
Compared with BZX384-B51-Q, the BZX384-A51-QX delivers tighter regulation and lower impedance for precision analog functions; versus MMSZ5257B-TP, it trades absolute power for automotive qualification, smaller size, and superior accuracy - making it optimal for space- and reliability-critical automotive modules.
Availability
BZX384-A51-QX is available at Aetrix Electronics and suitable for automotive engine control units, industrial 4–20 mA sensor transmitters, and power supply overvoltage protection circuits requiring stable component supply with AEC-Q101 compliance and ±1 % voltage accuracy.
Supply support for BZX384-A51-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 high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified components and energy-efficient solutions.
The BZX384-Q series belongs to Nexperia's automotive-grade Zener regulator portfolio, designed specifically for precision voltage reference and transient suppression in harsh-environment electronic control systems.
FAQ
What is the maximum continuous forward current for BZX384-A51-QX?
The BZX384-A51-QX is a Zener diode intended for reverse-bias operation; its absolute maximum forward current is 250 mA per limiting values table. However, forward conduction is not its functional mode - sustained forward bias exceeds safe operating area and risks thermal runaway. Designers must ensure cathode remains at higher potential than anode during regulation.
How does the temperature coefficient affect regulation accuracy over automotive temperature range?
At +12.6 mV/K, the BZX384-A51-QX exhibits positive temperature drift: VZ increases ~1.26 V from −40 °C to +125 °C. Combined with ±1 % initial tolerance, total variation remains within ±2.1 % across −40 °C to +125 °C - verified in characteristics tables and acceptable for most automotive reference applications.
Can BZX384-A51-QX replace BZX384-C51-Q in an existing design?
No - BZX384-C51-Q has ±5 % tolerance (48 V–54 V) and higher 500 Ω rdif. Substituting the ±1 % BZX384-A51-QX may cause over-regulation or instability in circuits tuned for wider VZ spread. Recalibration of feedback dividers and load current margins is required to maintain system-level accuracy and stability.
What is the recommended PCB layout for optimal thermal performance?
Mount BZX384-A51-QX on FR4 with single-sided 1 oz copper, using the standard SOD323 reflow footprint (2.2 mm × 1.65 mm solder lands). Maximize copper area connected to cathode pad to leverage 110 K/W junction-to-solder-point thermal resistance - avoid thermal isolation islands and ensure solder joint integrity per IPC-A-610 Class 2 guidelines.
BZX384-A51-QX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- BZX384-Q
- Package/Case:
- SC-76, SOD-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 51 V
- Tolerance:
- ±1%
- Power - Max:
- 300 mW
- Impedance (Max) (Zzt):
- 180 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 35.7 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.1 V @ 100 mA
- Operating Temperature:
- 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-323
BZX384-A51-QX FAQ
1.How can I place an order for BZX384-A51-QX through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX384-A51-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 BZX384-A51-QX reliable?
The price and inventory of BZX384-A51-QX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX384-A51-QX is usually 5 days.
3.What payment methods are accepted for BZX384-A51-QX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX384-A51-QX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX384-A51-QX?
BZX384-A51-QX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX384-A51-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 BZX384-A51-QX?
For technical support, including BZX384-A51-QX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX384-A51-QX requirements.
6.How does Aetrix verify that BZX384-A51-QX is sourced from the original manufacturer or authorized distributors?
All BZX384-A51-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 BZX384-A51-QX meets industry standards.
7.What is the process for return or replacement of BZX384-A51-QX?
All BZX384-A51-QX units undergo pre-shipment inspection (PSI). If there is an issue with BZX384-A51-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 BZX384-A51-QX part is unused and in its original packaging.
Return procedure for BZX384-A51-QX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX384-A51-QX Tags
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