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onsemi SZMMSZ5256ET1G
- Part No.:
- SZMMSZ5256ET1G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
SZMMSZ5256ET1G.pdf
- Description:
- DIODE ZENER 30V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:1,850
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Product details
Overview
SZMMSZ5256ET1G from onsemi is a 30 V ±5% Zener diode in SOD-123 package, rated for 500 mW power dissipation at 75 °C on FR-5 board, with 4.2 mA test current, 49 Ω dynamic impedance at IZT, and 0.1 µA leakage at 23 V reverse bias. It serves as a precision voltage reference or overvoltage clamp in low-power analog and power-supply feedback circuits.
For engineers reviewing the SZMMSZ5256ET1G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal derating behavior, junction-to-lead thermal resistance (150 °C/W), ESD robustness (>16 kV HBM), and SOD-123 footprint compatibility with high-density PCB layouts.
Technical Context
This device operates in reverse breakdown to maintain stable voltage regulation across varying load and temperature conditions. Its 30 V nominal Zener voltage is specified at 4.2 mA test current (IZT) with ±5% tolerance, and it exhibits a dynamic impedance of 49 Ω at IZT and 600 Ω at knee current (IZK = 0.25 mA).
Designed for surface-mount assembly on FR-4/FR-5 boards, the SZMMSZ5256ET1G features a thermally optimized SOD-123 package with 150 °C/W junction-to-lead thermal resistance and supports peak surge power up to 225 W (8 × 20 µs pulse). It meets AEC-Q101 for automotive applications and carries Class 3 ESD rating (>16 kV HBM).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 28.5 V (min) to 31.5 V (max) at IZT = 4.2 mA - defines regulated output range under standard test conditions |
| Power Dissipation (PD) | 500 mW at TL = 75 °C - maximum continuous power on FR-5 board before thermal derating applies |
| Zener Impedance (ZZT) | 49 Ω at IZT = 4.2 mA - determines voltage regulation stability under small-signal AC variations |
| Leakage Current (IR) | 0.1 µA max at VR = 23 V - ensures minimal standby current in clamping or reference configurations |
| Thermal Resistance (RJL) | 150 °C/W - enables accurate junction temperature estimation from lead temperature in layout-constrained designs |
| ESD Rating | Class 3 (>16 kV) per HBM - supports robust handling and operation in unshielded industrial environments |
| Peak Surge Power | 225 W (8 × 20 µs) - withstands transient overvoltage events without degradation |
Pinout & Package
The SZMMSZ5256ET1G is housed in a Pb-free SOD-123 plastic surface-mount package (Case 425, Style 1), measuring 1.60 × 2.69 × 1.16 mm, with cathode indicated by a polarity band. The package is void-free, transfer-molded, UL 94 V-0 rated, and rated for 260 °C soldering (10 s).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to regulated voltage node; reverse-biased terminal where Zener breakdown occurs |
| 2 (Non-banded End) | Anode | Connected to circuit ground or lower-potential reference; completes reverse-bias path |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 Qualified | Validated for automotive-grade reliability including temperature cycling, humidity, and mechanical stress testing |
| Small SOD-123 Footprint | Enables placement in space-constrained locations such as portable power modules and sensor signal conditioning stages |
| 500 mW Power Rating | Supports stable regulation in medium-current feedback loops without external heat sinking |
| Low Leakage at 23 V | Minimizes quiescent current draw in battery-powered voltage monitor circuits |
| High ESD Robustness | Eliminates need for additional ESD protection components in exposed I/O or interface lines |
Applications
| Power Supply Feedback | Overvoltage Clamp |
|---|---|
Use Scenario: Regulating output voltage in isolated flyback or buck-derived DC-DC converters using optocoupler feedback. IC Role / Device Role / Timing Role: Provides precise 30 V reference to error amplifier input, enabling tight output voltage control. Use Value: Maintains ±5% regulation accuracy across temperature and line/load variations due to stable VZ and low ZZT. | Use Scenario: Protecting microcontroller GPIO pins or ADC inputs from transient surges exceeding 23 V. IC Role / Device Role / Timing Role: Acts as shunt clamp, diverting excess current when reverse voltage exceeds 31.5 V. Use Value: Limits voltage excursion with <0.1 µA leakage below clamp threshold, preserving signal integrity during normal operation. |
| Reference Voltage Source | Temperature-Stable Bias Generator |
Use Scenario: Generating a stable bias point for op-amp comparators or analog front-end gain stages. IC Role / Device Role / Timing Role: Supplies fixed 30 V reference to resistor-divider networks defining operating points. Use Value: Delivers consistent voltage with <49 Ω dynamic impedance, minimizing drift under varying load currents. | Use Scenario: Establishing temperature-compensated bias for RF power amplifier stages in automotive telematics modules. IC Role / Device Role / Timing Role: Functions as primary reference in conjunction with NTC thermistors to offset thermal drift. Use Value: AEC-Q101 qualification ensures long-term stability across −55 °C to +150 °C ambient extremes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMSZ5256ET1G | No SZ prefix; not AEC-Q101 qualified; same electrical specs and SOD-123 package | Suitable for commercial/industrial use only; lacks automotive process controls and PPAP documentation | Select when automotive qualification is unnecessary and cost sensitivity is higher |
| BZX84-C30LT1G | 30 V ±5%, SOT-23 package, 350 mW rating, 60 Ω ZZT, 100 nA leakage at 23 V | Smaller footprint but lower power handling; requires different PCB land pattern and thermal design | Choose for ultra-compact layouts where 500 mW derating margin is acceptable |
Compared with MMSZ5256ET1G and BZX84-C30LT1G, the SZMMSZ5256ET1G uniquely combines automotive qualification, 500 mW power capability, and SOD-123 thermal performance-making it optimal for safety-critical or high-reliability power rail monitoring in automotive ECUs and industrial controllers.
Availability
SZMMSZ5256ET1G is available at Aetrix Electronics and suitable for automotive power management, industrial sensor signal conditioning, and consumer DC-DC converter feedback requiring stable component supply and full traceability.
Supply support for SZMMSZ5256ET1G 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
onsemi (Semiconductor Components Industries, LLC) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The MMSZ52xxET1G/SZMMSZ52xxET1G series was designed specifically for precision voltage regulation in space-constrained, high-reliability surface-mount applications-emphasizing thermal efficiency, ESD resilience, and AEC-Q101 compliance for automotive subsystems.
FAQ
What is the Zener voltage tolerance of SZMMSZ5256ET1G?
The SZMMSZ5256ET1G has a nominal Zener voltage of 30 V with a standard tolerance of ±5%, meaning its actual reverse breakdown voltage falls between 28.5 V and 31.5 V when tested at IZT = 4.2 mA and TL = 30 °C ±1 °C. This tolerance is confirmed in the Electrical Characteristics table on page 3 of the official onsemi datasheet for SZMMSZ5256ET1G.
Is SZMMSZ5256ET1G suitable for automotive applications?
Yes, SZMMSZ5256ET1G is AEC-Q101 qualified and PPAP capable, with manufacturing and testing performed under automotive-specific quality controls. The "SZ" prefix explicitly denotes compliance with automotive requirements, including extended temperature operation (−55 °C to +150 °C) and enhanced reliability validation-making SZMMSZ5256ET1G appropriate for engine control units, body electronics, and ADAS power rails.
What is the maximum power dissipation for SZMMSZ5256ET1G on a standard PCB?
SZMMSZ5256ET1G delivers 500 mW total power dissipation on an FR-5 board at lead temperature (TL) = 75 °C, with linear derating of 6.7 mW/°C above that temperature. This rating assumes use of the minimum recommended footprint (3.5 × 1.5 inches) and reflects real-world thermal performance-not just junction-to-ambient limits-enabling reliable operation in compact power designs.
How does the dynamic impedance of SZMMSZ5256ET1G affect voltage regulation accuracy?
The dynamic impedance (ZZT) of SZMMSZ5256ET1G is 49 Ω at IZT = 4.2 mA, directly determining how much the output voltage varies with changes in Zener current. Lower ZZT yields tighter regulation-e.g., a 1 mA load step causes only ~49 mV shift in regulated voltage. This value is measured at 1 kHz with AC current = 0.1 × IZT, per onsemi's test methodology for SZMMSZ5256ET1G.
What packaging and marking details apply to SZMMSZ5256ET1G?
SZMMSZ5256ET1G is supplied in Pb-free SOD-123 packages (Case 425, Style 1), tape-and-reel format (3,000 units per reel), with device marking "CD9" followed by a date code. The cathode is identified by a band on terminal 1; the package dimensions are 1.60 × 2.69 × 1.16 mm, and it complies with UL 94 V-0 flammability rating-fully documented in the Mechanical Case Outline section of the SZMMSZ5256ET1G datasheet.
SZMMSZ5256ET1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- SZMMSZ52xxxT1G
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 30 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 49 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 23 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -55°C ~ 150°C
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-123
SZMMSZ5256ET1G FAQ
1.How can I place an order for SZMMSZ5256ET1G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZMMSZ5256ET1G 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 SZMMSZ5256ET1G reliable?
The price and inventory of SZMMSZ5256ET1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZMMSZ5256ET1G is usually 5 days.
3.What payment methods are accepted for SZMMSZ5256ET1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZMMSZ5256ET1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZMMSZ5256ET1G?
SZMMSZ5256ET1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZMMSZ5256ET1G 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 SZMMSZ5256ET1G?
For technical support, including SZMMSZ5256ET1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZMMSZ5256ET1G requirements.
6.How does Aetrix verify that SZMMSZ5256ET1G is sourced from the original manufacturer or authorized distributors?
All SZMMSZ5256ET1G 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 SZMMSZ5256ET1G meets industry standards.
7.What is the process for return or replacement of SZMMSZ5256ET1G?
All SZMMSZ5256ET1G units undergo pre-shipment inspection (PSI). If there is an issue with SZMMSZ5256ET1G, 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 SZMMSZ5256ET1G part is unused and in its original packaging.
Return procedure for SZMMSZ5256ET1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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