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Nexperia USA Inc. BZX58550-B1V8-QX
- Part No.:
- BZX58550-B1V8-QX
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Zener Diodes
- Package:
- SC-79, SOD-523
- Datasheet:
-
BZX58550-B1V8-QX.pdf
- Description:
- DIODE ZENER 1.8V 270MW SOD523
- Quantity:
- Payment:
- Shipping:
Inventory:2,034
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Product details
Overview
BZX58550-B1V8-Q from Nexperia is a low-current Zener voltage regulator diode in SOD523 (SC-79) package, providing precise 1.8 V regulation at 50 µA test current, with ±2 % tolerance, 300 mW power dissipation, and AEC-Q101 qualification for automotive use.
For engineers reviewing the BZX58550-B1V8-Q datasheet, BZX58550-B1V8-Q pinout, BZX58550-B1V8-Q application, or BZX58550-B1V8-Q equivalent, this device serves as a compact, low-bias voltage reference in battery-powered sensor nodes, automotive body electronics, and portable power management circuits where space and leakage sensitivity are critical.
Technical Context
This Zener diode operates in reverse breakdown mode with a nominal working voltage of 1.8 V at IZ = 50 µA, exhibiting a differential resistance ≤600 Ω at 5 mA and a temperature coefficient of −3.5 mV/K. Its ultra-low test current enables stable regulation in micro-power systems.
The device features intentional cathode-side thermal design with Rth(j-a) = 460 K/W on standard FR4 and 285 K/W with 1 cm² copper pad, supporting reliable operation up to 150 °C junction temperature and qualified per AEC-Q101 for automotive under-hood applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 1.8 V at IZ = 50 µA - defines regulation point for low-bias reference circuits |
| Tolerance | ±2 % - ensures tight voltage accuracy without post-production trimming |
| Power Dissipation | 300 mW at Tamb ≤ 25 °C - supports continuous operation in compact PCB layouts with minimal copper area |
| Forward Voltage | ≤0.9 V at IF = 10 mA - enables predictable forward conduction during transient overvoltage events |
| Reverse Leakage | ≤1.0 µA at VR = 1.0 V - minimizes quiescent current in always-on battery systems |
| Junction Temperature | −55 °C to +150 °C - validated for extended automotive ambient ranges including engine bay mounting |
| Package | SOD523 (SC-79), 1.2 mm × 0.8 mm × 0.6 mm - enables high-density placement in space-constrained modules |
Pinout & Package
SOD523 (SC-79) ultra-small surface-mount plastic package with flat lead profile, 2-terminal configuration, and cathode marked by a bar on the top surface.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (K) | Cathode | Connected to regulated output node; marking bar identifies this terminal for correct PCB orientation |
| 2 (A) | Anode | Connected to ground or lower-potential rail; reverse-biased during Zener operation |
Key Features
| Feature | Design Value |
|---|---|
| Low test current operation | Specified at 50 µA - reduces bias network loading in ultra-low-power IoT sensors and wearables |
| AEC-Q101 qualification | Qualified for automotive applications - eliminates need for additional reliability screening in body control modules |
| Thermal performance | Rth(j-sp) = 65 K/W to solder point - enables direct thermal coupling to PCB copper for improved long-term stability |
| Leakage optimization | Controlled IR rise in B-series variants - balances noise suppression and regulation precision in analog front-ends |
| Compact footprint | 0.96 mm² board area - allows placement adjacent to ASICs or MCUs without compromising routing density |
Applications
| Automotive Body Control Unit | Portable Medical Sensor Node |
|---|---|
Use Scenario: Voltage reference for LIN transceiver biasing and microcontroller reset monitoring in door module ECUs. IC Role / Device Role / Timing Role: Zener regulator supplying stable 1.8 V to analog comparators and POR circuits. Use Value: AEC-Q101 qualification and −40 °C to +125 °C operation ensure functional safety compliance without derating. |
Use Scenario: Reference source for ADC in battery-powered pulse oximeter with 10-year shelf life requirement. IC Role / Device Role / Timing Role: Low-leakage voltage clamp maintaining reference integrity during multi-year standby. Use Value: 1.0 µA max reverse current at 1.0 V enables >15-year battery retention in coin-cell designs. |
| Industrial Wireless Sensor Transmitter | Consumer Wearable Power Monitor |
Use Scenario: Regulation for RF SoC supply rail in LoRaWAN endpoint operating on primary lithium thionyl chloride cells. IC Role / Device Role / Timing Role: Precision shunt regulator stabilizing LDO input under varying load and temperature. Use Value: ±2 % tolerance and −3.5 mV/K TC minimize calibration drift across −40 °C to +85 °C industrial range. |
Use Scenario: Overvoltage protection and reference generation in smartwatch battery fuel gauge IC interface. IC Role / Device Role / Timing Role: Dual-function device acting as both clamp and reference for coulomb counter analog inputs. Use Value: 0.9 V forward voltage limits fault energy during ESD events while preserving signal integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX58550-C1V8-Q | ±5 % tolerance, higher leakage (1.0 µA vs. 0.8 µA at VR = 1.0 V), same package and VZ range | Acceptable where cost sensitivity outweighs precision; less suitable for high-accuracy ADC references | Select when budget constraints dominate and system-level calibration compensates for wider tolerance |
| MMSZ4678T1G | 1.8 V, ±5 %, SOD-123 package (2.7 mm × 1.4 mm), 500 mW Ptot, not AEC-Q101 qualified | Larger footprint, higher power handling, no automotive qualification - limited to commercial-grade portable devices | Choose only for non-automotive applications requiring higher surge immunity and relaxed size constraints |
Compared with BZX58550-C1V8-Q, this part offers tighter voltage accuracy and lower leakage for precision analog functions; versus MMSZ4678T1G, it delivers automotive qualification and 44 % smaller board area at the expense of absolute power rating.
Availability
BZX58550-B1V8-Q is available at Aetrix Electronics and suitable for automotive body electronics, portable medical sensors, industrial wireless transmitters, and consumer wearables requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for BZX58550-B1V8-Q 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 delivering high-performance, reliable discrete, logic, and MOSFET devices with focus on efficiency, miniaturization, and automotive-grade robustness.
This device belongs to the BZX58550-Q series of low-current Zener regulators engineered specifically for space-constrained, low-power, and automotive-qualified voltage reference and clamping applications.
FAQ
What is the maximum continuous reverse voltage this diode can regulate at 25 °C?
The BZX58550-B1V8-Q is rated for nominal 1.8 V regulation at IZ = 50 µA. Its absolute maximum reverse voltage is defined by its Zener knee - operation beyond 2.04 V (max VZ) risks exceeding specified differential resistance and thermal limits. For sustained regulation, maintain VR between 1.76 V and 1.84 V under 50 µA test conditions.
Can this Zener diode be used in series with another for higher voltage reference generation?
No - the BZX58550-B1V8-Q is not designed for series stacking. Its low test current (50 µA) and tight tolerance rely on individual device characterization; cascading introduces mismatched leakage, thermal gradients, and uncontrolled current sharing that degrade accuracy and stability. Use a single higher-voltage Zener or dedicated reference IC instead.
Does the cathode marking bar indicate polarity during forward conduction or reverse breakdown?
The cathode marking bar indicates the cathode terminal, which must be held at a higher potential than the anode for reverse-bias (Zener) operation. During forward conduction, current flows anode-to-cathode - the bar remains a physical orientation guide, not a functional polarity indicator for forward mode.
Is the 300 mW power rating valid across the full −55 °C to +150 °C operating range?
No - the 300 mW rating applies only at Tamb ≤ 25 °C with specified PCB copper area (35 mm² at cathode tab). Derating is required above 25 °C: power capability drops linearly to zero at 150 °C junction temperature, governed by Rth(j-a) = 285 K/W under optimized layout conditions.
BZX58550-B1V8-QX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- BZX58550-Q
- Package/Case:
- SC-79, SOD-523
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 1.8 V
- Tolerance:
- ±2%
- Power - Max:
- 270 mW
- Impedance (Max) (Zzt):
- 100 Ohms
- Current - Reverse Leakage @ Vr:
- 7.5 µA @ 1 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:
- SOD-523
BZX58550-B1V8-QX FAQ
1.How can I place an order for BZX58550-B1V8-QX through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX58550-B1V8-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 BZX58550-B1V8-QX reliable?
The price and inventory of BZX58550-B1V8-QX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX58550-B1V8-QX is usually 5 days.
3.What payment methods are accepted for BZX58550-B1V8-QX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX58550-B1V8-QX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX58550-B1V8-QX?
BZX58550-B1V8-QX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX58550-B1V8-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 BZX58550-B1V8-QX?
For technical support, including BZX58550-B1V8-QX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX58550-B1V8-QX requirements.
6.How does Aetrix verify that BZX58550-B1V8-QX is sourced from the original manufacturer or authorized distributors?
All BZX58550-B1V8-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 BZX58550-B1V8-QX meets industry standards.
7.What is the process for return or replacement of BZX58550-B1V8-QX?
All BZX58550-B1V8-QX units undergo pre-shipment inspection (PSI). If there is an issue with BZX58550-B1V8-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 BZX58550-B1V8-QX part is unused and in its original packaging.
Return procedure for BZX58550-B1V8-QX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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