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Nexperia USA Inc. BZX384-A18-QX
- Part No.:
- BZX384-A18-QX
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-76, SOD-323
- Datasheet:
-
BZX384-A18-QX.pdf
- Description:
- DIODE ZENER 18V 300MW SOD323
- Quantity:
- Payment:
- Shipping:
Inventory:2,310
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Product details
Overview
BZX384-A18-QX from Nexperia is a ±1 % tolerance Zener voltage regulator diode in SOD323 (SC-76) package, rated for 18 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-A18-QX datasheet, BZX384-A18-QX pinout, BZX384-A18-QX application, or BZX384-A18-QX equivalent, this device serves as a precision low-power shunt regulator in ECU power rails, sensor biasing networks, and ADC reference stabilization where tight voltage tolerance and automotive-grade reliability are required.
Technical Context
This Zener diode operates in reverse-bias breakdown mode with a specified 18.0 V ±1 % working voltage at IZ = 5 mA, differential resistance ≤225 Ω, and temperature coefficient of +12.6 mV/K at IZ = 5 mA. Its non-repetitive peak reverse power dissipation is rated at 40 W for 100 μs pulses.
Designed for surface-mount use on FR4 PCBs with standard SOD323 footprint, it features cathode-marked anode-cathode polarity, junction-to-ambient thermal resistance of 415 K/W, and operates across -65 °C to +150 °C ambient temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Breakdown Voltage | 18.0 V ±1 % at IZ = 5 mA - ensures stable 18 V reference under nominal regulation current |
| Power Dissipation | 300 mW at Tamb ≤ 25 °C - defines maximum continuous DC power handling on standard FR4 PCB |
| Differential Resistance | ≤225 Ω at IZ = 5 mA - determines output impedance and load regulation sensitivity |
| Reverse Current | ≤0.05 μA at VR = 14.4 V - guarantees low leakage below regulation threshold |
| Forward Voltage | 0.9 V at IF = 10 mA - enables predictable forward conduction behavior during transient events |
| Peak Pulse Power | 40 W for tp = 100 μs - supports surge suppression in automotive load-dump scenarios |
| Junction Temperature | 150 °C maximum - sets thermal derating limit for high-temperature automotive environments |
Pinout & Package
SOD323 (SC-76) plastic surface-mounted package with 2 leads; cathode identified by marking bar on body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Cathode (K) | Connected to regulated output node; carries reverse breakdown current during regulation |
| 2 | Anode (A) | Connected to ground or lower-potential rail; establishes reference potential for Zener operation |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive applications including engine control units and ADAS power domains |
| ±1 % voltage tolerance | Enables precise voltage clamping without post-production trimming in safety-critical circuits |
| Low thermal resistance | Rth(j-sp) = 110 K/W to solder point - improves thermal coupling to PCB for sustained pulse handling |
| Small SOD323 footprint | 1.35 mm × 0.85 mm body size - supports high-density layout in space-constrained modules |
| Non-repetitive surge rating | 40 W peak reverse power - withstands ISO 7637-2 pulse 1 and pulse 2a transients without degradation |
Applications
| Automotive ECU Power Rail Clamping | Industrial Sensor Bias Reference |
|---|---|
Use Scenario: Stabilizing 18 V supply rail in engine control unit against battery transients and alternator ripple. IC Role / Device Role / Timing Role: Shunt regulator providing low-impedance voltage clamp during overvoltage events. Use Value: Maintains rail integrity within ±1 % tolerance while absorbing up to 40 W surge energy per pulse. |
Use Scenario: Generating stable 18 V bias for analog front-end amplifiers in pressure and temperature sensors. IC Role / Device Role / Timing Role: Precision voltage reference establishing fixed operating point for signal conditioning circuitry. Use Value: Delivers <0.05 μA leakage at 14.4 V, minimizing sensor offset drift and enabling sub-mV measurement accuracy. |
| ADC Reference Stabilization | Overvoltage Protection in Telematics Modules |
Use Scenario: Supplying clean 18 V reference to 16-bit SAR ADC in vehicle infotainment system power management IC. IC Role / Device Role / Timing Role: Low-noise voltage reference source decoupling ADC from noisy digital supply domains. Use Value: 225 Ω differential resistance ensures minimal reference droop under dynamic load switching conditions. |
Use Scenario: Protecting CAN transceiver input pins from load-dump spikes exceeding 24 V in telematics gateway units. IC Role / Device Role / Timing Role: Fast-acting shunt clamp limiting transient voltage to 18.18 V maximum during 100 μs surges. Use Value: AEC-Q101 qualification guarantees operational reliability after 1000+ surge cycles in harsh automotive environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX384-B18-Q | ±2 % tolerance (17.6 V–18.4 V), higher max IR (0.05 μA vs. 0.05 μA), identical package and power rating | Acceptable where tighter regulation not required; lower cost for non-safety-critical subsystems | Select when ±2 % tolerance satisfies system margin requirements and cost optimization is prioritized |
| MMSZ4689T1G | 18 V ±5 %, SOD-123 package, 500 mW Ptot, Rth(j-a) = 350 K/W, not AEC-Q101 qualified | Higher power handling but lacks automotive qualification and tighter tolerance | Use only in industrial or consumer applications where AEC-Q101 compliance is not mandated |
Compared with BZX384-B18-Q, the A18-QX provides tighter voltage control critical for precision references; versus MMSZ4689T1G, it trades higher power capability for guaranteed automotive reliability and superior thermal performance in compact layouts.
Availability
BZX384-A18-QX is available at Aetrix Electronics and suitable for automotive ECU design, industrial sensor interface development, and telematics module production requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for BZX384-A18-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 leading global semiconductor manufacturer specializing in high-performance, high-reliability discrete and logic devices, with core expertise in automotive-qualified components.
The BZX384-Q series belongs to Nexperia's automotive Zener diode product line, engineered specifically for precision voltage regulation and transient suppression in demanding vehicular power systems.
FAQ
What is the maximum reverse voltage before breakdown for BZX384-A18-QX?
The nominal Zener voltage is 18.0 V ±1 %, meaning breakdown occurs between 17.82 V and 18.18 V at test current IZ = 5 mA. Below 14.4 V, reverse current remains ≤0.05 μA - well within safe non-conduction limits for upstream circuit protection.
Can BZX384-A18-QX be used in parallel for higher power dissipation?
No - Zener diodes exhibit negative temperature coefficients and mismatched VZ tolerances, causing current hogging and thermal runaway when paralleled. For higher power, use a single higher-rated device or external series resistor with forced-air cooling per Nexperia's thermal guidelines.
Is the SOD323 package compatible with standard reflow soldering profiles?
Yes - the device is qualified for lead-free reflow per J-STD-020, with peak temperature up to 260 °C. Recommended footprint matches Nexperia's Figure 12: 0.6 mm pad width, 1.1 mm pad length, and 0.5 mm solder mask clearance for optimal wetting and void control.
How does temperature affect regulation accuracy in automotive under-hood environments?
At IZ = 5 mA, the temperature coefficient is +12.6 mV/K; over -40 °C to +125 °C ambient, this introduces ±1.5 V drift. System-level compensation requires either external thermistor networks or selection of higher-VZ variants with reduced TC above 6 V.
BZX384-A18-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):
- 18 V
- Tolerance:
- ±1%
- Power - Max:
- 300 mW
- Impedance (Max) (Zzt):
- 45 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 12.6 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-A18-QX FAQ
1.How can I place an order for BZX384-A18-QX through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX384-A18-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-A18-QX reliable?
The price and inventory of BZX384-A18-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-A18-QX is usually 5 days.
3.What payment methods are accepted for BZX384-A18-QX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX384-A18-QX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX384-A18-QX?
BZX384-A18-QX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX384-A18-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-A18-QX?
For technical support, including BZX384-A18-QX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX384-A18-QX requirements.
6.How does Aetrix verify that BZX384-A18-QX is sourced from the original manufacturer or authorized distributors?
All BZX384-A18-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-A18-QX meets industry standards.
7.What is the process for return or replacement of BZX384-A18-QX?
All BZX384-A18-QX units undergo pre-shipment inspection (PSI). If there is an issue with BZX384-A18-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-A18-QX part is unused and in its original packaging.
Return procedure for BZX384-A18-QX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX384-A18-QX Tags
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