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onsemi SZ1SMB5949BT3G
- Part No.:
- SZ1SMB5949BT3G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SZ1SMB5949BT3G.pdf
- Description:
- DIODE ZENER 100V 3W SMB
- Quantity:
- Payment:
- Shipping:
Inventory:2,721
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Product details
Overview
SZ1SMB5949BT3G from onsemi is a 3 W surface-mount Zener diode with nominal zener voltage of 100 V, ±5% tolerance, 3.7 mA test current (IZT), and 3100 Ω maximum dynamic impedance at IZT - used for precision voltage regulation and overvoltage protection in DC power supplies and automotive control modules.
For engineers reviewing the SZ1SMB5949BT3G datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage stability under thermal drift, surge power handling up to 100 W (tp = 1 ms), AEC−Q101 qualification for automotive use, and SMB package compatibility with automated SMT assembly.
Technical Context
This device operates as a two-terminal voltage reference diode, conducting in reverse breakdown when reverse bias exceeds its 100 V nominal zener voltage. Its 3100 Ω dynamic impedance at 3.7 mA ensures predictable regulation under light-load conditions.
Thermal derating begins at 75°C junction temperature, with 40 mW/°C reduction above that point; total thermal resistance from junction-to-lead is 25 °C/W, enabling effective heat transfer to PCB copper when mounted per recommended footprint on FR-4 board.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 95 V min / 100 V nom / 105 V max - defines regulated output voltage range under IZT = 3.7 mA |
| Power Dissipation (PD) | 3.0 W @ TL = 75°C - maximum steady-state power at lead temperature, derates linearly above 75°C |
| Zener Impedance (ZZT) | 3100 Ω max @ IZT = 3.7 mA - limits voltage variation under small-signal AC load changes |
| Leakage Current (IR) | 0.25 μA max @ VR = 76 V - ensures minimal standby current in high-impedance bias networks |
| Surge Power (PPK) | 100 W peak @ tp = 1 ms - supports transient overvoltage clamping without failure |
| ESD Rating | Class 3 (>16 kV HBM) - withstands electrostatic discharge during handling and assembly |
| AEC−Q101 Qualified | Yes - validated for automotive-grade reliability including temperature cycling, humidity, and mechanical stress |
Pinout & Package
Package: SMB (Case 403A), surface-mount plastic package with modified L-bend leads, cathode indicated by polarity band, UL 94 V-0 flammability rating, Pb-free construction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connects to lower-potential node in reverse-bias configuration; carries forward current up to 200 mA |
| Cathode | Reverse breakdown terminal | Connects to higher-potential node; defines regulated voltage reference point at 100 V nominal |
Key Features
| Feature | Design Value |
|---|---|
| Flat handling surface | Enables accurate pick-and-place placement during automated SMT assembly without tombstoning |
| Top-side or bottom-side mounting | Package symmetry allows flexible PCB layout with either side facing up or down |
| Modified L-bend leads | Increases solder joint contact area for improved mechanical strength and thermal conduction |
| Polarity band marking | Unambiguous cathode identification prevents reverse installation in high-voltage circuits |
| Void-free molded plastic case | Eliminates internal delamination risk under thermal cycling, supporting long-term automotive reliability |
Applications
| Automotive Engine Control Unit (ECU) | Industrial DC Power Supply Monitoring |
|---|---|
Use Scenario: Regulating reference voltage for microcontroller ADC inputs in engine management systems exposed to 12 V battery transients. IC Role / Device Role / Timing Role: Zener voltage reference providing stable 100 V clamp for overvoltage protection of downstream analog circuitry. Use Value: Maintains signal integrity during load-dump events (ISO 7637-2 Pulse 5a) due to 100 W surge capability and AEC−Q101 qualification. |
Use Scenario: Stabilizing feedback loop in isolated 48 V telecom power supply where primary-side sensing requires precise high-voltage reference. IC Role / Device Role / Timing Role: Precision voltage clamp ensuring consistent regulation despite input ripple and line variations. Use Value: Low leakage (0.25 μA @ 76 V) minimizes error in high-impedance voltage divider networks used for sensing. |
| LED Driver Overvoltage Protection | Test Equipment High-Voltage Reference |
Use Scenario: Clamping transient spikes across constant-current LED strings in outdoor signage operating from unregulated 100–120 VAC-derived DC rails. IC Role / Device Role / Timing Role: Passive overvoltage suppressor absorbing energy during lightning-induced surges. Use Value: 3100 Ω ZZT ensures minimal voltage shift under fast-rising transients while maintaining 100 V threshold accuracy. |
Use Scenario: Providing calibrated 100 V reference in portable multimeter calibration fixtures requiring traceable voltage standards. IC Role / Device Role / Timing Role: Two-terminal passive voltage standard with known ±5% tolerance and low temperature coefficient above 12 V. Use Value: Stable 100 V nominal value enables direct comparison against DMM accuracy specs without active circuitry. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMSZ5267ET1G | 500 mW rating, 100 V nominal, SOD-123 package, 170 Ω ZZT @ 5 mA | Lower power handling; suited for signal-level clamping, not power rail regulation | Select when board space is constrained and surge energy is <1 J |
| BZX84-C100LT1G | 350 mW rating, 100 V nominal, SOT-23 package, 500 Ω ZZT @ 5 mA | Smaller footprint but limited to 100 mA IZM; no AEC−Q101 qualification | Choose for cost-sensitive consumer electronics where automotive qualification is unnecessary |
Compared with MMSZ5267ET1G and BZX84-C100LT1G, SZ1SMB5949BT3G delivers 6× higher power dissipation and AEC−Q101 compliance - making it the only option among the three suitable for automotive power rail stabilization and industrial surge suppression.
Availability
SZ1SMB5949BT3G is available at Aetrix Electronics and suitable for automotive ECU designs, industrial DC power monitoring, LED driver protection, and test equipment reference circuits requiring stable component supply with full traceability and long-lifecycle support.
Supply support for SZ1SMB5949BT3G 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 (Semiconductor Components Industries, LLC) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
SZ1SMB5949BT3G belongs to the SZ1SMB59xxT3G series - engineered specifically for AEC−Q101-compliant automotive voltage regulation and high-reliability industrial clamping where 3 W power handling and robust surge immunity are required.
FAQ
What is the maximum continuous power dissipation for SZ1SMB5949BT3G at 25°C ambient?
SZ1SMB5949BT3G is rated for 550 mW at TA = 25°C, with linear derating of 4.4 mW/°C above that temperature. This value assumes proper PCB copper area per the recommended footprint on FR-4 board; actual dissipation depends on thermal design and airflow. The 3.0 W rating applies only at TL = 75°C with heatsinking via leads.
Is SZ1SMB5949BT3G suitable for automotive applications?
Yes, SZ1SMB5949BT3G is AEC−Q101 qualified and PPAP capable, with testing covering temperature cycling, humidity, mechanical shock, and high-temperature reverse bias. Its SZ prefix confirms automotive-specific site and change control requirements, making it appropriate for engine control, body electronics, and ADAS power domains.
What is the zener voltage tolerance and test condition for SZ1SMB5949BT3G?
SZ1SMB5949BT3G has a ±5% zener voltage tolerance, specified as 95 V (min), 100 V (nom), and 105 V (max) measured at IZT = 3.7 mA and TL = 30°C. This tolerance reflects manufacturing variation and does not include temperature coefficient effects, which are negligible above 12 V.
How does the dynamic impedance of SZ1SMB5949BT3G affect regulation accuracy?
SZ1SMB5949BT3G exhibits 3100 Ω maximum dynamic impedance at IZT = 3.7 mA, meaning a 1 mA change in zener current causes up to ~3.1 V shift in output voltage. For tight regulation, maintain IZ > 5 mA or pair with a buffer amplifier; this impedance value is typical for high-voltage Zeners and acceptable in clamping applications.
What is the maximum surge power rating for SZ1SMB5949BT3G and under what waveform?
SZ1SMB5949BT3G supports 100 W peak surge power for 1 ms rectangular nonrepetitive pulses at TJ = 25°C prior to initial pulse. This rating aligns with IEC 61000-4-5 Level 3 surge immunity requirements and enables reliable operation during load-dump transients in 12 V automotive systems.
SZ1SMB5949BT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-214AA, SMB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 100 V
- Tolerance:
- ±5%
- Power - Max:
- 3 W
- Impedance (Max) (Zzt):
- 250 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 76 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
SZ1SMB5949BT3G FAQ
1.How can I place an order for SZ1SMB5949BT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZ1SMB5949BT3G 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 SZ1SMB5949BT3G reliable?
The price and inventory of SZ1SMB5949BT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZ1SMB5949BT3G is usually 5 days.
3.What payment methods are accepted for SZ1SMB5949BT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZ1SMB5949BT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZ1SMB5949BT3G?
SZ1SMB5949BT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZ1SMB5949BT3G 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 SZ1SMB5949BT3G?
For technical support, including SZ1SMB5949BT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZ1SMB5949BT3G requirements.
6.How does Aetrix verify that SZ1SMB5949BT3G is sourced from the original manufacturer or authorized distributors?
All SZ1SMB5949BT3G 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 SZ1SMB5949BT3G meets industry standards.
7.What is the process for return or replacement of SZ1SMB5949BT3G?
All SZ1SMB5949BT3G units undergo pre-shipment inspection (PSI). If there is an issue with SZ1SMB5949BT3G, 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 SZ1SMB5949BT3G part is unused and in its original packaging.
Return procedure for SZ1SMB5949BT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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