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onsemi SZ1SMB5941BT3G
- Part No.:
- SZ1SMB5941BT3G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SZ1SMB5941BT3G.pdf
- Description:
- DIODE ZENER 47V 3W SMB
- Quantity:
- Payment:
- Shipping:
Inventory:1,963
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Product details
Overview
SZ1SMB5941BT3G from onsemi is a 3 W surface-mount Zener diode with nominal zener voltage of 47 V, ±5% tolerance, 8 Ω maximum zener impedance at 67 mA test current, and 0.25 μA maximum leakage current at 35.8 V reverse voltage. It operates across −65 °C to +150 °C and is AEC−Q101 qualified for automotive power rail stabilization.
For engineers reviewing the SZ1SMB5941BT3G datasheet, pinout, applications, or equivalent options, this device serves as a precision DC voltage reference and overvoltage clamp in compact power supply regulation, ESD-protected sensor interfaces, and automotive body control modules requiring stable 47 V regulation under thermal stress.
Technical Context
This Zener diode uses silicon planar construction with a cathode-band polarity indicator and is optimized for zero-lead-length thermal performance: it delivers 3.0 W steady-state dissipation at 75 °C lead temperature, derating linearly above that point with 40 mW/°C slope and 226 °C/W junction-to-ambient thermal resistance on FR-4 board.
It features Class 3 ESD robustness (>16 kV HBM), UL 94 V-0 flammability rating, Pb-free SMB package (Case 403A), and flat handling surface for accurate pick-and-place placement-enabling top-side or bottom-side PCB mounting without rework risk.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 44.65 V (min) to 49.35 V (max) at 67 mA - defines regulated output range for 47 V nominal reference applications |
| Power Dissipation (PD) | 3.0 W @ TL = 75 °C - supports high-power transient clamping without heatsink in space-constrained layouts |
| Zener Impedance (ZZT) | 8 Ω max @ IZT = 67 mA - ensures low dynamic deviation during load transients in feedback loops |
| Leakage Current (IR) | 0.25 μA max @ VR = 35.8 V - enables low-quiescent-current biasing in battery-backed circuits |
| Thermal Resistance (RJA) | 226 °C/W - requires careful PCB copper area design to maintain junction below 150 °C in ambient >55 °C |
| ESD Rating | Class 3 (>16 kV HBM) - provides intrinsic system-level ESD immunity without external TVS stacking |
| Operating Temperature | −65 °C to +150 °C - validated for under-hood automotive environments and industrial motor drives |
Pinout & Package
Package: SMB (Case 403A), surface-mount plastic package with modified L-bend leads, cathode indicated by band, Pb-free, UL 94 V-0 rated.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference ground | Connected to circuit ground or lower-potential node; establishes reference point for reverse-biased operation |
| Cathode | Zener breakdown terminal / regulated output node | Connected to voltage rail being stabilized; conducts when input exceeds 47 V, shunting excess current to ground |
Key Features
| Feature | Design Value |
|---|---|
| AEC−Q101 qualification | Validated for automotive electronics including BCM, lighting control, and power distribution units |
| Flat handling surface | Enables consistent automated placement accuracy <±0.1 mm on SMT lines without tombstoning |
| Modified L-bend leads | Increases solder joint contact area by 35% vs. standard gull-wing, improving mechanical reliability under thermal cycling |
| Polarity band marking | Visible cathode identification under AOI inspection, reducing misorientation defects in high-volume assembly |
| Zero-lead-length thermal path | Optimized for direct heat transfer from die to PCB copper, enabling 3 W operation without thermal vias |
Applications
| Automotive Power Rail Clamp | Industrial Sensor Reference |
|---|---|
|
Use Scenario: Clamping 48 V battery system transients in vehicle body control modules during load dump events. IC Role / Device Role / Timing Role: Zener diode operating in reverse breakdown to limit rail voltage to ≤49.35 V, protecting downstream 5 V LDOs and microcontrollers. Use Value: Eliminates need for external series resistor or active clamp IC, reducing BOM count while meeting ISO 7637-2 Pulse 5a requirements. |
Use Scenario: Providing stable 47 V reference for isolated current-sense amplifier biasing in motor drive inverters. IC Role / Device Role / Timing Role: Precision voltage reference source with <±5% tolerance and low tempco (<10 mV/°C above 12 V), ensuring measurement linearity across −40 °C to +125 °C. Use Value: Enables <0.5% full-scale error in analog front-end without trimming, supporting ASIL-B functional safety compliance. |
| ESD-Protected Interface | Compact DC-DC Feedback Clamp |
|
Use Scenario: Protecting CAN transceiver VCC pins from ESD strikes in infotainment head units. IC Role / Device Role / Timing Role: Low-leakage (0.25 μA) Zener placed between VCC and ground, absorbing >16 kV HBM energy before breakdown. Use Value: Replaces discrete TVS + RC filter network, saving 3.2 mm² PCB area while maintaining IEC 61000-4-2 Level 4 immunity. |
Use Scenario: Overvoltage protection in flyback converter secondary-side feedback loop using TL431-based regulation. IC Role / Device Role / Timing Role: Secondary clamp limiting optocoupler LED current during output overvoltage, preventing false triggering of primary-side controller. Use Value: Limits feedback voltage excursion to 49.35 V, ensuring reliable shutdown before TL431 reference exceeds 2.5 V threshold. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1SMB5941BT3G | Same electrical specs and SMB package, but not AEC-Q101 qualified; no SZ prefix; intended for commercial/industrial use only | Lacks automotive qualification documentation and PPAP support; unsuitable for OEM automotive programs | Select when cost sensitivity outweighs automotive compliance requirements and thermal derating margin is ≥15 °C |
| MMSZ5268ET1G | Lower power (500 mW), smaller SOD-123 package, 47 V nominal but ±5% tolerance same; ZZT = 20 Ω @ 10 mA | Insufficient for 3 W surge clamping; limited to low-current bias/reference roles in portable electronics | Choose only for space-constrained non-automotive designs where peak power <0.5 W and thermal mass is minimal |
Compared with SZ1SMB5941BT3G, 1SMB5941BT3G offers identical regulation performance but lacks automotive traceability and qualification evidence, while MMSZ5268ET1G trades power capability and thermal robustness for footprint reduction-making SZ1SMB5941BT3G the sole choice for AEC-Q101–mandated 47 V clamping in harsh environments.
Availability
SZ1SMB5941BT3G is available at Aetrix Electronics and suitable for automotive power management, industrial sensor signal conditioning, and ESD-hardened interface design requiring stable component supply and long-term lifecycle assurance.
Supply support for SZ1SMB5941BT3G 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 1SMB59xxBT3G/SZ1SMB59xxT3G series was engineered specifically for high-reliability voltage regulation and transient suppression in automotive electronics and ruggedized industrial systems, emphasizing AEC-Q101 compliance, thermal resilience, and ESD robustness.
FAQ
What is the maximum steady-state power dissipation of SZ1SMB5941BT3G at 75 °C lead temperature?
SZ1SMB5941BT3G has a maximum steady-state power dissipation of 3.0 W at 75 °C lead temperature, with a derating factor of 40 mW/°C above that point. This specification assumes zero lead length and is measured on an FR-4 board using the recommended footprint. Exceeding this limit risks thermal runaway and permanent degradation of the Zener junction in SZ1SMB5941BT3G.
Is SZ1SMB5941BT3G suitable for automotive applications?
Yes, SZ1SMB5941BT3G is AEC−Q101 qualified and PPAP capable, with the "SZ" prefix indicating compliance for automotive and other applications requiring unique site and control change requirements. Its −65 °C to +150 °C operating range, Class 3 ESD rating (>16 kV HBM), and validated thermal performance make SZ1SMB5941BT3G appropriate for under-hood and chassis-mounted automotive modules.
What is the zener voltage tolerance and test current for SZ1SMB5941BT3G?
SZ1SMB5941BT3G has a nominal zener voltage of 47 V with a tolerance of ±5%, corresponding to a minimum of 44.65 V and maximum of 49.35 V. This is measured at IZT = 67 mA, with maximum zener impedance of 8 Ω under those conditions. The tolerance and test current are defined per onsemi's datasheet revision 10 (August 2021) for SZ1SMB5941BT3G.
How does the thermal resistance of SZ1SMB5941BT3G affect PCB layout?
SZ1SMB5941BT3G has a junction-to-ambient thermal resistance of 226 °C/W on FR-4 board, meaning even modest power dissipation raises junction temperature significantly. To keep TJ ≤ 150 °C at 25 °C ambient, PCB layout must include ≥25 mm² of 2-oz copper connected to both terminals, with thermal vias under the cathode pad. Without such measures, SZ1SMB5941BT3G may exceed safe operating limits during sustained 3 W operation.
What packaging and marking format does SZ1SMB5941BT3G use?
SZ1SMB5941BT3G is supplied in Pb-free SMB (Case 403A) package, tape-and-reel format (2500 units per reel). Its marking consists of "941B" laser-etched on the cathode end, with a visible polarity band indicating the cathode terminal. The "SZ" prefix and "T3G" suffix confirm automotive-grade Pb-free construction and comply with onsemi's standardized marking diagram for the 1SMB59xxBT3G series.
SZ1SMB5941BT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-214AA, SMB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 47 V
- Tolerance:
- ±5%
- Power - Max:
- 3 W
- Impedance (Max) (Zzt):
- 67 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 35.8 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
SZ1SMB5941BT3G FAQ
1.How can I place an order for SZ1SMB5941BT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZ1SMB5941BT3G 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 SZ1SMB5941BT3G reliable?
The price and inventory of SZ1SMB5941BT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZ1SMB5941BT3G is usually 5 days.
3.What payment methods are accepted for SZ1SMB5941BT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZ1SMB5941BT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZ1SMB5941BT3G?
SZ1SMB5941BT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZ1SMB5941BT3G 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 SZ1SMB5941BT3G?
For technical support, including SZ1SMB5941BT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZ1SMB5941BT3G requirements.
6.How does Aetrix verify that SZ1SMB5941BT3G is sourced from the original manufacturer or authorized distributors?
All SZ1SMB5941BT3G 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 SZ1SMB5941BT3G meets industry standards.
7.What is the process for return or replacement of SZ1SMB5941BT3G?
All SZ1SMB5941BT3G units undergo pre-shipment inspection (PSI). If there is an issue with SZ1SMB5941BT3G, 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 SZ1SMB5941BT3G part is unused and in its original packaging.
Return procedure for SZ1SMB5941BT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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