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onsemi SZ1SMB5944BT3G
- Part No.:
- SZ1SMB5944BT3G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SZ1SMB5944BT3G.pdf
- Description:
- DIODE ZENER 62V 3W SMB
- Quantity:
- Payment:
- Shipping:
Inventory:750
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Product details
Overview
SZ1SMB5944BT3G from onsemi is a 3 W surface-mount Zener diode with nominal Zener voltage of 62 V, ±5% tolerance, 6 mA test current (IZT), and maximum dynamic impedance of 1500 Ω at IZT - designed for precision voltage regulation and overvoltage protection in automotive power rails and industrial DC supplies.
For engineers reviewing the SZ1SMB5944BT3G datasheet, pinout, applications, or equivalent options, this device serves as a stable, AEC−Q101 qualified voltage reference in compact SMB packages where thermal robustness, ESD resilience (>16 kV HBM), and tight voltage tolerance are critical selection criteria.
Technical Context
This Zener regulator operates in reverse breakdown mode with specified VZ measured at IZT = 6 mA and TL = 30°C. Its 1500 Ω maximum Zener impedance at IZT and 0.25 μA maximum leakage current at VR = 47.1 V reflect low-noise, high-stability regulation performance under steady-state DC conditions.
The device features a modified L-bend lead configuration for enhanced solder joint reliability, UL 94 V−0 flammability rating, and Pb−free construction compliant with RoHS. It is rated for −65°C to +150°C operating temperature and supports top-side or bottom-side PCB mounting per its flat handling surface design.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 62 V nominal (58.9–65.1 V range); enables precise clamping in 48 V and 60 V system rails. |
| Power Dissipation (PD) | 3.0 W @ TL = 75°C; supports sustained regulation without forced cooling in thermally constrained layouts. |
| Zener Test Current (IZT) | 6 mA; defines the operating point where VZ and ZZT are guaranteed per datasheet. |
| Zener Impedance (ZZT) | ≤1500 Ω @ IZT; ensures minimal output voltage variation under load transients. |
| Leakage Current (IR) | ≤0.25 μA @ VR = 47.1 V; guarantees negligible standby power loss in high-impedance bias networks. |
| Thermal Resistance (RJL) | 40 °C/W junction-to-lead; allows accurate thermal modeling when mounted to copper pour or heatsink pad. |
| ESD Rating | Class 3 (>16 kV HBM); provides robust handling and in-system immunity without external protection. |
Pinout & Package
Package: SMB (Case 403A), surface-mount plastic package with cathode polarity band. Dimensions: 3.56 mm × 4.32 mm × 1.02 mm (L × W × H), with modified L-bend leads for improved pad contact area.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener reference ground node | Connected to circuit ground or lower-potential rail; establishes reference potential for reverse-biased operation. |
| Cathode | Zener breakdown terminal / regulated output node | Connected to protected node or voltage rail; delivers stable 62 V clamp during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| AEC−Q101 qualification | Validated for automotive power systems requiring extended temperature cycling and long-term reliability. |
| ±5% Zener voltage tolerance | Reduces binning requirements and simplifies BOM management across production lots. |
| 16 kV HBM ESD rating | Eliminates need for discrete ESD protection in board-level surge paths. |
| Void-free transfer-molded plastic case | Ensures consistent thermal performance and mechanical integrity during reflow and thermal cycling. |
| UL 94 V−0 flammability rating | Meets safety standards for industrial and transportation equipment enclosures. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Reference Supply |
|---|---|
Use Scenario: Clamping transient spikes on 48 V battery-derived power rails in ADAS ECUs and body control modules. IC Role / Device Role / Timing Role: Zener voltage regulator providing overvoltage protection and stable reference for LDO input stages. Use Value: Withstands repetitive 100 V surges while maintaining <65.1 V clamping threshold and ≤1500 Ω dynamic impedance. |
Use Scenario: Generating a stable 62 V bias for high-voltage sensor front-ends in factory automation current monitors. IC Role / Device Role / Timing Role: Precision shunt reference enabling accurate scaling of 0–100 V analog inputs. Use Value: Delivers ±5% voltage accuracy and <0.25 μA leakage at 47.1 V, minimizing measurement drift in high-impedance dividers. |
| Telecom DC-DC Converter Feedback | Test Equipment Overvoltage Clamp |
Use Scenario: Secondary-side voltage sensing in isolated 60 V telecom rectifiers using optocoupler feedback loops. IC Role / Device Role / Timing Role: Zener reference stabilizing error amplifier input in flyback or forward converter feedback networks. Use Value: Maintains 62 V regulation with ≤1500 Ω impedance at 6 mA, ensuring loop stability across temperature and line variations. |
Use Scenario: Input-stage overvoltage protection in portable multimeters and bench power supplies rated up to 75 V. IC Role / Device Role / Timing Role: Fast-acting shunt clamp limiting input voltage during accidental probe misconnection. Use Value: Activates at 58.9 V minimum with 3 W steady-state dissipation capability, preventing downstream IC damage without crowbar action. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1SMB5944BT3G | Same electrical specs and SMB package, but not AEC−Q101 qualified; lacks automotive change control (SZ prefix). | Approved for commercial/industrial use only; excluded from automotive PPAP documentation. | Select when AEC−Q101 compliance is unnecessary and cost sensitivity outweighs qualification requirements. |
| BZX84-C62LT1G | Lower power (350 mW), SOT-23 package; Zener voltage 62 V ±5%, but higher ZZT (up to 120 Ω) and no AEC−Q101 rating. | Suitable for low-current biasing, not for 3 W clamping or automotive environments. | Choose only for space-constrained, low-power applications where thermal margin and automotive qualification are not required. |
Compared with SZ1SMB5944BT3G, 1SMB5944BT3G offers identical regulation performance but lacks automotive traceability and PPAP support, while BZX84-C62LT1G trades power handling and ruggedness for footprint reduction - making SZ1SMB5944BT3G the sole choice for AEC−Q101-compliant 3 W Zener regulation.
Availability
SZ1SMB5944BT3G is available at Aetrix Electronics and suitable for automotive power rail protection, industrial sensor reference supplies, and telecom DC-DC converter feedback circuits requiring stable component supply with full AEC−Q101 documentation and traceable Pb−free sourcing.
Supply support for SZ1SMB5944BT3G 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 silicon solutions for automotive, industrial, cloud, medical, and IoT applications - with emphasis on reliability, safety, and sustainability.
The 1SMB59xxBT3G/SZ1SMB59xxT3G series was developed specifically for high-reliability voltage regulation in harsh-environment applications, combining AEC−Q101 qualification, high ESD immunity, and robust thermal performance in standard SMB packaging.
FAQ
What is the Zener voltage tolerance for SZ1SMB5944BT3G?
The SZ1SMB5944BT3G has a Zener voltage tolerance of ±5%, with a nominal value of 62 V and a guaranteed range of 58.9 V to 65.1 V at IZT = 6 mA and TL = 30°C. This tolerance is explicitly defined in the Electrical Characteristics table on page 3 of the onsemi datasheet, and applies to all devices marked SZ1SMB5944BT3G.
Is SZ1SMB5944BT3G qualified for automotive applications?
Yes, SZ1SMB5944BT3G is AEC−Q101 qualified and PPAP capable, as confirmed in the Features section of the onsemi datasheet. The "SZ" prefix denotes automotive-grade manufacturing controls, site-specific change management, and full qualification testing - distinguishing it from the commercial-grade 1SMB5944BT3G variant.
What is the maximum power dissipation of SZ1SMB5944BT3G at 75°C lead temperature?
The maximum steady-state power dissipation for SZ1SMB5944BT3G is 3.0 W at TL = 75°C, with a derating factor of 25 mW/°C above that temperature. This value is specified in the Maximum Ratings table on page 1 of the datasheet and reflects the device's ability to sustain regulation under thermally demanding conditions when properly mounted.
Does SZ1SMB5944BT3G have ESD protection, and what level is specified?
SZ1SMB5944BT3G features an ESD rating of Class 3 (>16 kV) per Human Body Model (HBM), as stated in the Features section of the onsemi datasheet. This high-level ESD immunity is built into the device structure and does not require external protection components in typical board-level handling or operation.
What is the cathode marking convention for SZ1SMB5944BT3G?
The cathode of SZ1SMB5944BT3G is indicated by a polarity band on the SMB package body, as shown in the Mechanical Case Outline diagram on page 6 of the datasheet. This band aligns with the cathode terminal and must be oriented toward the higher-potential node during PCB layout to ensure correct reverse-bias operation.
SZ1SMB5944BT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-214AA, SMB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 62 V
- Tolerance:
- ±5%
- Power - Max:
- 3 W
- Impedance (Max) (Zzt):
- 100 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 47.1 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
SZ1SMB5944BT3G FAQ
1.How can I place an order for SZ1SMB5944BT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZ1SMB5944BT3G 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 SZ1SMB5944BT3G reliable?
The price and inventory of SZ1SMB5944BT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZ1SMB5944BT3G is usually 5 days.
3.What payment methods are accepted for SZ1SMB5944BT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZ1SMB5944BT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZ1SMB5944BT3G?
SZ1SMB5944BT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZ1SMB5944BT3G 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 SZ1SMB5944BT3G?
For technical support, including SZ1SMB5944BT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZ1SMB5944BT3G requirements.
6.How does Aetrix verify that SZ1SMB5944BT3G is sourced from the original manufacturer or authorized distributors?
All SZ1SMB5944BT3G 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 SZ1SMB5944BT3G meets industry standards.
7.What is the process for return or replacement of SZ1SMB5944BT3G?
All SZ1SMB5944BT3G units undergo pre-shipment inspection (PSI). If there is an issue with SZ1SMB5944BT3G, 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 SZ1SMB5944BT3G part is unused and in its original packaging.
Return procedure for SZ1SMB5944BT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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