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onsemi SZMMSZ5257ET1G
- Part No.:
- SZMMSZ5257ET1G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
SZMMSZ5257ET1G.pdf
- Description:
- DIODE ZENER 33V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:2,880
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Product details
Overview
SZMMSZ5257ET1G from onsemi is a 33 V ±5% Zener diode in SOD-123 package, rated for 500 mW power dissipation at 75 °C on FR-5 board, with 700 Ω maximum dynamic impedance at 3.8 mA test current and 0.1 µA reverse leakage at 25 V, used for precision voltage regulation and overvoltage protection in power supply feedback loops.
For engineers reviewing the SZMMSZ5257ET1G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal derating behavior, junction-to-lead thermal resistance, and AEC-Q101 qualification status for automotive-grade reliability validation.
Technical Context
This device operates as a two-terminal silicon Zener diode optimized for stable reverse-bias voltage reference and transient suppression. Its 33 V nominal Zener voltage is specified at 3.8 mA test current (IZT), with temperature coefficient near zero crossing in the 30–40 V range per typical characterization data.
It features Class 3 ESD robustness (>16 kV HBM), 225 W nonrepetitive surge capability (8 × 20 µs pulse), and junction-to-lead thermal resistance of 150 °C/W - enabling reliable operation under pulsed load conditions and moderate ambient temperatures without heatsinking.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 33 V ±5% at IZT = 3.8 mA - defines precise clamping threshold for feedback or protection circuits |
| Maximum Dynamic Impedance | 700 Ω at IZT = 3.8 mA - determines voltage regulation stability under varying load current |
| Reverse Leakage Current | 0.1 µA max at VR = 25 V - ensures minimal standby power loss in high-impedance bias networks |
| Power Dissipation | 500 mW at TL = 75 °C, derated 6.7 mW/°C above - sets usable thermal envelope on standard PCBs |
| Junction-to-Lead Thermal Resistance | 150 °C/W - supports localized heat transfer to PCB copper, critical for pulse handling |
| ESD Rating | Class 3 (>16 kV) per HBM - qualifies for handling in uncontrolled assembly environments |
| AEC-Q101 Qualified | Yes - validates suitability for automotive electronics requiring extended temperature and reliability compliance |
Pinout & Package
SOD-123 surface-mount package: 2-pin, 1.60 mm × 2.69 mm × 1.16 mm body, cathode marked by band, void-free thermosetting plastic case rated UL 94 V-0.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to regulated output or higher-potential node; reverse-bias anode connection point |
| 2 (Unmarked End) | Anode | Connected to ground or lower-potential reference; completes Zener conduction path |
Key Features
| Feature | Design Value |
|---|---|
| Automotive-grade qualification | AEC-Q101 qualified and PPAP capable - enables direct use in Tier-1 automotive subsystems without requalification |
| High surge robustness | 225 W peak power (8 × 20 µs) - withstands common transient events like load dump or inductive kick |
| Pb-free and RoHS compliant | SZ-prefix indicates controlled manufacturing site with automotive change control - ensures supply chain traceability and material compliance |
| Optimized for automated placement | SOD-123 footprint designed for high-yield pick-and-place assembly - reduces placement misalignment risk in high-density layouts |
Applications
| Switch-Mode Power Supply Feedback | Automotive Body Control Module |
|---|---|
Use Scenario: Regulates output voltage in isolated flyback or forward converter feedback path via optocoupler interface. IC Role / Device Role / Timing Role: Precision voltage reference providing stable 33 V clamp for TL431-type shunt regulator circuits. Use Value: Tight ±5% Zener tolerance and low dynamic impedance ensure <±1% output regulation accuracy across line/load/temperature. | Use Scenario: Protects microcontroller I/O pins and sensor interfaces against battery transients in 12 V vehicle systems. IC Role / Device Role / Timing Role: Overvoltage clamp limiting input voltage to 33 V during load-dump events (ISO 7637-2 Pulse 5a). Use Value: 225 W surge rating and AEC-Q101 qualification guarantee survival and functional integrity during repeated 120 V/100 ms transients. |
| Industrial Sensor Signal Conditioning | Medical Equipment Power Monitoring |
Use Scenario: Stabilizes excitation voltage for bridge-based pressure or strain sensors in PLC analog input modules. IC Role / Device Role / Timing Role: Low-leakage (0.1 µA @ 25 V) Zener reference establishing accurate 33 V bias for instrumentation amplifiers. Use Value: Minimal leakage prevents gain error drift in high-impedance sensor bias networks, maintaining <0.01% full-scale error. | Use Scenario: Monitors auxiliary DC rail voltage in diagnostic imaging equipment with redundant power supervision logic. IC Role / Device Role / Timing Role: Fail-safe voltage threshold detector triggering shutdown if 33 V rail drops below 31.4 V (−5%) or exceeds 34.7 V (+5%). Use Value: Guaranteed ±5% tolerance and −55 °C to +150 °C operating range ensure reliable trip-point consistency across clinical operating environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMSZ5257ET1G | No SZ prefix; not AEC-Q101 qualified; identical electrical specs and SOD-123 package | Intended for commercial/industrial use only; lacks automotive change control and PPAP documentation | Select when AEC-Q101 compliance is not required and cost sensitivity outweighs qualification overhead |
| BZX84-C33LT1G | 33 V ±5%, 350 mW rating, SOT-23 package, 60 Ω Zzt @ 5 mA - lower power, lower impedance, different footprint | Used in space-constrained portable electronics; requires PCB redesign due to 3-pin SOT-23 vs. 2-pin SOD-123 | Select when lower dynamic impedance and smaller board area are prioritized over surge robustness and automotive qualification |
Compared with MMSZ5257ET1G and BZX84-C33LT1G, SZMMSZ5257ET1G uniquely combines AEC-Q101 qualification, 500 mW continuous power, and 225 W surge capability in the compact SOD-123 form factor - making it the only option qualified for automotive power rail protection without layout changes.
Availability
SZMMSZ5257ET1G is available at Aetrix Electronics and suitable for automotive body control modules, industrial power supply feedback networks, and medical equipment voltage supervision requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SZMMSZ5257ET1G 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.
SZMMSZ52xxET1G series belongs to onsemi's automotive-qualified Zener regulator portfolio, engineered specifically for robust voltage reference and transient protection in harsh-environment electronic control units.
FAQ
What is the Zener voltage tolerance for SZMMSZ5257ET1G?
The SZMMSZ5257ET1G has a nominal Zener voltage of 33 V with a standard tolerance of ±5%, meaning the actual measured voltage falls between 31.35 V and 34.65 V when tested at 3.8 mA (IZT) and thermal equilibrium at 30 °C. This tolerance is guaranteed across the full operating temperature range and is verified per AEC-Q101 stress testing protocols for the SZ-prefix variant.
Is SZMMSZ5257ET1G suitable for automotive applications?
Yes, SZMMSZ5257ET1G is AEC-Q101 qualified and PPAP capable, with manufacturing traceability and change control specific to automotive requirements. Its −55 °C to +150 °C operating range, 225 W surge rating, and Class 3 ESD robustness make it suitable for engine control units, body electronics, and ADAS power domains where reliability under thermal and electrical stress is mandatory.
What is the maximum power dissipation of SZMMSZ5257ET1G on a standard PCB?
SZMMSZ5257ET1G delivers 500 mW total power dissipation on FR-5 board at lead temperature (TL) of 75 °C, derating linearly at 6.7 mW/°C above that point. At 25 °C ambient, practical dissipation is limited by junction-to-ambient thermal resistance (340 °C/W); full 500 mW is achievable only with adequate copper pour and thermal vias to maintain TL ≤ 75 °C.
How does the dynamic impedance of SZMMSZ5257ET1G affect voltage regulation accuracy?
The SZMMSZ5257ET1G has a maximum dynamic impedance (ZZT) of 700 Ω at 3.8 mA test current. This value directly impacts regulation accuracy: for every 1 mA change in Zener current, output voltage shifts up to 0.7 V. In feedback applications, this necessitates stable bias current design and may require additional filtering to suppress ripple-induced variation in regulated output.
What packaging and marking identify SZMMSZ5257ET1G on the SOD-123 body?
SZMMSZ5257ET1G uses the SOD-123 package with cathode indicated by a band at Pin 1. The device marking is "CE1", followed by a date code and Pb-free indicator (microdot or "G"). This marking aligns with onsemi's generic SOD-123 marking diagram and distinguishes it from commercial MMSZ5257ET1G (same "CE1" marking but no SZ prefix in ordering code).
SZMMSZ5257ET1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- SZMMSZ52xxxT1G
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 33 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 58 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 25 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
SZMMSZ5257ET1G FAQ
1.How can I place an order for SZMMSZ5257ET1G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZMMSZ5257ET1G 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 SZMMSZ5257ET1G reliable?
The price and inventory of SZMMSZ5257ET1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZMMSZ5257ET1G is usually 5 days.
3.What payment methods are accepted for SZMMSZ5257ET1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZMMSZ5257ET1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZMMSZ5257ET1G?
SZMMSZ5257ET1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZMMSZ5257ET1G 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 SZMMSZ5257ET1G?
For technical support, including SZMMSZ5257ET1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZMMSZ5257ET1G requirements.
6.How does Aetrix verify that SZMMSZ5257ET1G is sourced from the original manufacturer or authorized distributors?
All SZMMSZ5257ET1G 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 SZMMSZ5257ET1G meets industry standards.
7.What is the process for return or replacement of SZMMSZ5257ET1G?
All SZMMSZ5257ET1G units undergo pre-shipment inspection (PSI). If there is an issue with SZMMSZ5257ET1G, 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 SZMMSZ5257ET1G part is unused and in its original packaging.
Return procedure for SZMMSZ5257ET1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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