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onsemi SZMMSZ5251BT1G
- Part No.:
- SZMMSZ5251BT1G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
SZMMSZ5251BT1G.pdf
- Description:
- DIODE ZENER 22V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:6,728
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Product details
Overview
SZMMSZ5251BT1G from onsemi is a 22 V ±5% Zener diode in SOD−123 package, rated for 500 mW power dissipation at TL = 75°C, with 5.6 mA test current (IZT), 29 Ω dynamic impedance (ZZT), and 0.1 µA reverse leakage at 17 V (VR). It serves as a precision voltage reference or overvoltage clamp in low-power analog and power supply feedback circuits.
For engineers reviewing the SZMMSZ5251BT1G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal equilibrium operation, junction-to-ambient thermal resistance (340 °C/W), ESD robustness (>16 kV HBM), and AEC−Q101 qualification for automotive use.
Technical Context
This device operates under thermal equilibrium conditions at TL = 30°C ±1°C for nominal Zener voltage measurement, ensuring stable regulation across temperature. Its 22 V nominal Zener voltage exhibits a positive temperature coefficient typical of mid-voltage Zeners in this series.
The SOD−123 package enables automated assembly and supports 500 mW dissipation on FR−5 board with defined derating (6.7 mW/°C above 75°C). Junction-to-lead thermal resistance is 150 °C/W, supporting localized heat extraction in compact layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 20.9–23.1 V @ IZT = 5.6 mA - defines regulated output range under standard test conditions |
| Power Dissipation (PD) | 500 mW @ TL = 75°C - maximum steady-state power handling on FR−5 board |
| Zener Impedance (ZZT) | 29 Ω @ IZT = 5.6 mA - indicates regulation stiffness; lower values improve load regulation |
| Reverse Leakage (IR) | 0.1 µA @ VR = 17 V - ensures minimal standby current in clamping or reference applications |
| Thermal Resistance (RJA) | 340 °C/W - determines junction temperature rise above ambient at given power |
| ESD Rating | Class 3 (>16 kV HBM) - supports robust handling in automated manufacturing and field environments |
| AEC−Q101 Qualified | Yes - validated for automotive electronics per stress test requirements |
Pinout & Package
SOD−123 surface-mount plastic package (1.60 × 2.69 × 1.16 mm), void-free thermosetting case with cathode polarity band marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to regulated voltage node; current flows into cathode during Zener conduction |
| 2 (Non-banded End) | Anode | Connected to circuit ground or lower-potential rail; completes bias path for reverse breakdown |
Key Features
| Feature | Design Value |
|---|---|
| 500 mW Power Rating | Enables use in medium-current reference and protection circuits without heatsinking on standard PCBs |
| ±5% Zener Voltage Tolerance | Supports cost-sensitive designs where tight regulation is balanced against BOM simplicity |
| Pb-Free & RoHS Compliant | Meets global environmental compliance requirements for industrial and automotive production |
| Automated Assembly Optimized | Package geometry and finish ensure reliable pick-and-place and reflow soldering yield |
| High ESD Robustness | Eliminates need for external ESD protection in many interface and sensor signal conditioning paths |
Applications
| Automotive Sensor Reference | Industrial Power Supply Feedback |
|---|---|
Use Scenario: Providing stable 22 V reference for analog front-end circuits in engine control units and battery monitoring systems. IC Role / Device Role / Timing Role: Voltage reference element in precision ADC bias networks and op-amp gain-setting circuits. Use Value: AEC−Q101 qualification and thermal equilibrium voltage stability ensure long-term accuracy under under-hood temperature cycling. |
Use Scenario: Regulating feedback voltage in isolated DC−DC converters and linear post-regulators for PLC I/O modules. IC Role / Device Role / Timing Role: Shunt regulator in optocoupler-coupled feedback loops to maintain output voltage accuracy within ±1%. Use Value: 29 Ω ZZT and 0.1 µA leakage minimize regulation error and standby loss across line/load variations. |
| Consumer Device Overvoltage Clamp | Medical Instrument Signal Conditioning |
Use Scenario: Clamping transient surges on USB power rails and display backlight drivers in portable electronics. IC Role / Device Role / Timing Role: Transient voltage suppressor protecting downstream LDOs and microcontrollers from >24 V spikes. Use Value: Fast response to overvoltage events combined with Class 3 ESD rating reduces need for additional TVS stages. |
Use Scenario: Setting bias points and limiting input voltage excursions in patient-connected ECG amplifier front-ends. IC Role / Device Role / Timing Role: Precision shunt reference stabilizing gain resistors and protecting instrumentation amplifiers from fault conditions. Use Value: Low leakage (0.1 µA) prevents signal offset drift; Pb-free construction satisfies medical regulatory traceability requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMSZ5251BT1G | No AEC−Q101 qualification; identical electrical specs and SOD−123 package | Not approved for automotive production; suitable for industrial/commercial grade designs | Select when automotive qualification is not required and cost optimization is prioritized |
| BZX84-C22LT1G | 22 V ±5%, 350 mW rating, 60 Ω ZZT, SOT−23 package | Lower power and higher impedance limit use in precision references; smaller footprint allows ultra-dense layouts | Choose for space-constrained consumer applications where 500 mW headroom is unnecessary |
Compared with MMSZ5251BT1G and BZX84-C22LT1G, SZMMSZ5251BT1G uniquely combines automotive qualification, 500 mW capability, and 29 Ω impedance-making it optimal for safety-critical or thermally demanding voltage reference roles where reliability and regulation fidelity are non-negotiable.
Availability
SZMMSZ5251BT1G is available at Aetrix Electronics and suitable for automotive sensor modules, industrial power supplies, consumer overvoltage protection circuits, and medical signal conditioning requiring stable component supply and full traceability.
Supply support for SZMMSZ5251BT1G 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 is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The MMSZ52xxxT1G/SZMMSZ52xxxT1G series was designed for high-reliability, surface-mount Zener regulation in space-constrained and thermally challenging environments-emphasizing manufacturability, consistency, and automotive-grade robustness.
FAQ
What is the Zener voltage tolerance of SZMMSZ5251BT1G?
SZMMSZ5251BT1G has a ±5% Zener voltage tolerance, with a specified range of 20.9 V to 23.1 V at IZT = 5.6 mA and thermal equilibrium (TL = 30°C ±1°C). This tolerance is confirmed in the "5% TOLERANCE FG ELECTRICAL CHARACTERISTICS" table on page 3 of the onsemi datasheet, and applies directly to the SZMMSZ5251BT1G variant as part of the SZ-prefix automotive-qualified family.
Is SZMMSZ5251BT1G qualified for automotive applications?
Yes, SZMMSZ5251BT1G is AEC−Q101 qualified and PPAP capable, as explicitly stated in the "Features" section of the onsemi datasheet. The "SZ" prefix denotes devices meeting unique site and control change requirements for automotive and other high-reliability applications-distinguishing it from the standard MMSZ5251BT1G variant.
What is the maximum power dissipation for SZMMSZ5251BT1G on an FR−5 board?
SZMMSZ5251BT1G is rated for 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 value is listed in the "MAXIMUM RATINGS" table on page 1 of the official onsemi datasheet and applies specifically to the SOD−123 package configuration used by SZMMSZ5251BT1G.
What is the Zener impedance of SZMMSZ5251BT1G and why does it matter?
SZMMSZ5251BT1G has a maximum Zener impedance (ZZT) of 29 Ω at IZT = 5.6 mA, measured with 1 kHz AC signal at 0.1× DC current. This low impedance ensures minimal voltage variation under changing load current-critical for maintaining accuracy in feedback loops and reference circuits where SZMMSZ5251BT1G is deployed.
How is polarity marked on the SZMMSZ5251BT1G SOD−123 package?
SZMMSZ5251BT1G uses a cathode band marking on the SOD−123 case to indicate Pin 1 (cathode); Pin 2 (anode) is the unmarked end. This polarity identification is documented in the "Mechanical Characteristics" section and illustrated in the "MARKING DIAGRAM" on page 1 of the onsemi datasheet, and is consistent across all MMSZ52xxxT1G and SZMMSZ52xxxT1G variants.
SZMMSZ5251BT1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- SZMMSZ52xxxT1G
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 22 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 29 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 17 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
SZMMSZ5251BT1G FAQ
1.How can I place an order for SZMMSZ5251BT1G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZMMSZ5251BT1G 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 SZMMSZ5251BT1G reliable?
The price and inventory of SZMMSZ5251BT1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZMMSZ5251BT1G is usually 5 days.
3.What payment methods are accepted for SZMMSZ5251BT1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZMMSZ5251BT1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZMMSZ5251BT1G?
SZMMSZ5251BT1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZMMSZ5251BT1G 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 SZMMSZ5251BT1G?
For technical support, including SZMMSZ5251BT1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZMMSZ5251BT1G requirements.
6.How does Aetrix verify that SZMMSZ5251BT1G is sourced from the original manufacturer or authorized distributors?
All SZMMSZ5251BT1G 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 SZMMSZ5251BT1G meets industry standards.
7.What is the process for return or replacement of SZMMSZ5251BT1G?
All SZMMSZ5251BT1G units undergo pre-shipment inspection (PSI). If there is an issue with SZMMSZ5251BT1G, 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 SZMMSZ5251BT1G part is unused and in its original packaging.
Return procedure for SZMMSZ5251BT1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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