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onsemi SZ1SMB5948BT3G
- Part No.:
- SZ1SMB5948BT3G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SZ1SMB5948BT3G.pdf
- Description:
- DIODE ZENER 91V 3W SMB
- Quantity:
- Payment:
- Shipping:
Inventory:4,038
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Product details
Overview
SZ1SMB5948BT3G from onsemi is a 3 W surface-mount Zener diode with nominal Zener voltage of 91 V, ±5% tolerance, 4.1 mA test current (IZT), and maximum Zener impedance of 4.1 Ω at IZT - used for precision voltage regulation and overvoltage protection in automotive power supplies and industrial DC rails.
For engineers reviewing the SZ1SMB5948BT3G datasheet, pinout, applications, or equivalent options, this device is selected for stable 91 V clamping in high-reliability 12 V–48 V system rails where AEC−Q101 qualification, 16 kV HBM ESD rating, and SMB package thermal performance are required.
Technical Context
This Zener regulator operates in reverse breakdown mode with a specified VZ of 86.45–95.55 V at IZT = 4.1 mA, exhibiting low dynamic impedance (ZZT = 4.1 Ω) and tight temperature coefficient behavior above 75 V. Its thermal resistance from junction-to-lead is 40 °C/W, enabling 3.0 W dissipation at TL = 75°C.
The device features a modified L-bend lead form in the SMB (Case 403A) package, polarity band marking for cathode identification, and Pb-free construction qualified to AEC−Q101 - confirming suitability for automotive electronics requiring PPAP documentation and zero-lead-length thermal management.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 86.45–95.55 V @ IZT = 4.1 mA - defines precise clamping threshold for 91 V nominal rail protection |
| Power Dissipation (PD) | 3.0 W @ TL = 75°C - supports continuous operation in thermally constrained PCB layouts |
| Zener Impedance (ZZT) | 4.1 Ω @ IZT - ensures minimal voltage deviation under load transients up to 4.1 mA |
| Leakage Current (IR) | 0.25 μA @ VR = 69.2 V - guarantees low standby power loss in high-impedance bias networks |
| Max DC Zener Current (IZM) | 16 A - sets absolute safe operating limit for surge current handling without degradation |
| ESD Rating | Class 3 (>16 kV HBM) - enables robust handling in automated SMT assembly without ESD mitigation |
| Operating Temperature | −65°C to +150°C - validated for under-hood automotive and industrial ambient extremes |
Pinout & Package
Package: SMB (Case 403A), surface-mount plastic package with flat handling surface, modified L-bend leads, and cathode polarity band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener reference node | Connected to lower-potential side of regulated rail; establishes reference for reverse-bias operation |
| Cathode | Zener breakdown terminal / voltage clamp output | Connected to protected node; sinks current when voltage exceeds 91 V, limiting transient excursions |
Key Features
| Feature | Design Value |
|---|---|
| AEC−Q101 qualification | Validated for automotive power modules requiring PPAP documentation and stress testing compliance |
| 16 kV HBM ESD rating | Eliminates need for external ESD protection during board handling and reflow soldering |
| SMB package thermal performance | 40 °C/W junction-to-lead resistance enables full 3 W dissipation with minimal board copper area |
| ±5% Zener voltage tolerance | Reduces binning requirements and simplifies BOM management across 91 V design variants |
| Pb-free construction | Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity level 1 |
Applications
| Automotive Engine Control Unit (ECU) Power Rail Clamp | Industrial 48 V DC Distribution Monitoring |
|---|---|
Use Scenario: Clamps transients on 12 V battery-supplied ECU input rails during load dump events per ISO 7637-2 Pulse 5a. IC Role / Device Role / Timing Role: Zener voltage regulator providing passive overvoltage protection without control logic or response delay. Use Value: Maintains rail integrity below 95.6 V during 120 V/100 ms pulses, preventing damage to downstream MCUs and CAN transceivers. |
Use Scenario: Stabilizes reference voltage for analog monitoring circuits in 48 V telecom power shelves. IC Role / Device Role / Timing Role: Precision shunt regulator establishing fixed 91 V reference for ADC input scaling and fault detection thresholds. Use Value: Enables ±0.5% measurement accuracy over −40°C to +125°C due to low ZZT and predictable TC above 75 V. |
| LED Driver Overvoltage Protection | Programmable Power Supply Feedback Divider Clamp |
Use Scenario: Protects constant-current LED driver ICs from bus overvoltage during hot-swap or capacitor discharge events. IC Role / Device Role / Timing Role: Fast-acting shunt clamp activated within nanoseconds of exceeding 91 V, independent of control loop timing. Use Value: Prevents catastrophic failure of high-side MOSFETs and gate drivers by limiting drain-source voltage to ≤95.6 V. |
Use Scenario: Limits feedback node voltage in digitally adjustable DC-DC converters to prevent erroneous regulation during startup or fault conditions. IC Role / Device Role / Timing Role: Secondary voltage clamp placed across upper resistor of feedback divider network. Use Value: Guarantees error amplifier input stays within 0–2.5 V range even if DAC or microcontroller fails high, ensuring graceful shutdown. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1SMB5948BT3G | Same electrical specs and SMB package; lacks AEC−Q101 qualification and SZ-prefix automotive traceability | Approved for commercial/industrial use only; not suitable for automotive PPAP-controlled production | Select when cost sensitivity outweighs automotive compliance requirements and no vehicle-level validation is needed |
| BZX84-C91LT1G | Lower power (350 mW), SOT-23 package, 91 V ±5%, but higher ZZT (70 Ω) and no AEC−Q101 rating | Limited to low-current bias/reference roles; cannot sustain 3 W surges or replace SZ1SMB5948BT3G in power rail clamping | Use only in space-constrained, low-power signal conditioning - not a functional substitute for SZ1SMB5948BT3G in power applications |
Compared with 1SMB5948BT3G and BZX84-C91LT1G, SZ1SMB5948BT3G uniquely combines AEC−Q101 qualification, 3 W power handling, and 4.1 Ω dynamic impedance - making it the sole choice for automotive-grade 91 V clamping where reliability, thermal margin, and process control are mandatory.
Availability
SZ1SMB5948BT3G is available at Aetrix Electronics and suitable for automotive ECU protection, industrial 48 V power monitoring, and LED driver overvoltage suppression requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for SZ1SMB5948BT3G 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 (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensor, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
SZ1SMB5948BT3G belongs to the SZ1SMB59xxT3G series - engineered specifically for AEC−Q101-compliant automotive electronics, emphasizing high-voltage stability, ESD resilience, and thermal robustness in harsh environments.
FAQ
What is the Zener voltage tolerance for SZ1SMB5948BT3G?
The SZ1SMB5948BT3G has a ±5% Zener voltage tolerance, resulting in a guaranteed reverse breakdown range of 86.45 V to 95.55 V at IZT = 4.1 mA. This tolerance is confirmed in the Electrical Characteristics table on page 3 of the onsemi datasheet and applies directly to the SZ1SMB5948BT3G device marking "948B".
Is SZ1SMB5948BT3G suitable for automotive applications?
Yes, SZ1SMB5948BT3G is AEC−Q101 qualified and PPAP capable, with explicit automotive traceability via the "SZ" prefix. It meets stringent stress testing requirements for temperature cycling, humidity, and mechanical shock - making it approved for engine control units, body electronics, and ADAS power systems where reliability is critical.
What is the maximum steady-state power dissipation for SZ1SMB5948BT3G?
SZ1SMB5948BT3G delivers 3.0 W maximum steady-state power dissipation at TL = 75°C with zero lead length, derating linearly at 25 mW/°C above that temperature. Its thermal resistance from junction-to-lead is 40 °C/W, enabling reliable operation in compact PCB layouts without forced airflow.
Does SZ1SMB5948BT3G have ESD protection built-in?
Yes, SZ1SMB5948BT3G is rated Class 3 (>16 kV) per Human Body Model (HBM), verified per ANSI/ESDA/JEDEC JS-001. This ESD robustness is intrinsic to its structure and packaging - eliminating the need for external TVS devices during SMT handling or board-level integration.
What package type does SZ1SMB5948BT3G use?
SZ1SMB5948BT3G uses the SMB (Case 403A) surface-mount plastic package, measuring 3.56 mm × 4.32 mm × 1.02 mm with modified L-bend leads and cathode polarity band. The package drawing and footprint dimensions are fully specified in the mechanical outline section of the onsemi datasheet.
SZ1SMB5948BT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-214AA, SMB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 91 V
- Tolerance:
- -
- Power - Max:
- 3 W
- Impedance (Max) (Zzt):
- 200 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 69.2 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
SZ1SMB5948BT3G FAQ
1.How can I place an order for SZ1SMB5948BT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZ1SMB5948BT3G 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 SZ1SMB5948BT3G reliable?
The price and inventory of SZ1SMB5948BT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZ1SMB5948BT3G is usually 5 days.
3.What payment methods are accepted for SZ1SMB5948BT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZ1SMB5948BT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZ1SMB5948BT3G?
SZ1SMB5948BT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZ1SMB5948BT3G 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 SZ1SMB5948BT3G?
For technical support, including SZ1SMB5948BT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZ1SMB5948BT3G requirements.
6.How does Aetrix verify that SZ1SMB5948BT3G is sourced from the original manufacturer or authorized distributors?
All SZ1SMB5948BT3G 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 SZ1SMB5948BT3G meets industry standards.
7.What is the process for return or replacement of SZ1SMB5948BT3G?
All SZ1SMB5948BT3G units undergo pre-shipment inspection (PSI). If there is an issue with SZ1SMB5948BT3G, 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 SZ1SMB5948BT3G part is unused and in its original packaging.
Return procedure for SZ1SMB5948BT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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