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onsemi 1SMB51AT3G
- Part No.:
- 1SMB51AT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB51AT3G.pdf
- Description:
- TVS DIODE 51VWM 82.4VC 425TEPBGA
- Quantity:
- Payment:
- Shipping:
Inventory:7,676
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Product details
Overview
1SMB51AT3G from ON Semiconductor is a unidirectional 600 W peak power Zener transient voltage suppressor (TVS) in SMB package, designed for parallel overvoltage protection of sensitive electronics. It features a 51 V working peak reverse voltage (VRWM), 59.7 V nominal breakdown voltage (VBR) at 1 mA test current, and clamps to ≤82.4 V at 7.3 A peak pulse current (IPP), making it suitable for automotive power line surge suppression and industrial DC supply rail protection.
For engineers reviewing the 1SMB51AT3G datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage margin vs. protected IC's absolute maximum rating, VRWM alignment with system operating voltage, thermal derating above 75°C, and UL 497B recognition for isolated loop circuit compliance.
Technical Context
The 1SMB51AT3G operates as a unidirectional Zener-based TVS diode, leveraging avalanche breakdown to clamp transients within nanoseconds. Its low zener impedance and <1.0 ns typical response time enable fast suppression of ESD and lightning-induced surges without affecting normal signal integrity.
It is rated for 600 W peak pulse power (10/1000 µs waveform), supports 100 A forward surge current (8.3 ms half-sine), and maintains <5 µA leakage at VRWM - critical for low-power standby circuits. Thermal resistance from junction-to-lead is 25 °C/W, enabling reliable operation up to +150 °C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 51 V - Maximum continuous reverse operating voltage before clamping begins; must exceed system DC bus voltage by ≥10% to avoid false triggering. |
| VBR (min/typ/max) | 56.1 / 59.7 / 63.15 V @ 1 mA - Ensures predictable turn-on threshold across process variation and temperature. |
| VC @ IPP | 82.4 V @ 7.3 A - Clamping voltage under standardized 10/1000 µs surge; defines worst-case stress on downstream components. |
| Peak Pulse Power | 600 W @ 1 ms - Sustains high-energy transients common in automotive load-dump and industrial switching events. |
| Leakage Current | <5 µA @ 51 V - Minimizes quiescent power loss in battery-backed or energy-sensitive systems. |
| ESD Rating | Class 3 HBM (>16 kV) - Meets IEC 61000-4-2 Level 4 for robust board-level ESD immunity without external shielding. |
| UL Recognition | UL 497B QVGQ2 - Certified for use in isolated loop protection circuits, including telecom and process control interfaces. |
Pinout & Package
Package: SMB (Case 403A), surface-mount, Pb-free, void-free thermosetting plastic with modified L-bend leads and cathode polarity band. Mounting position is unrestricted; max soldering temperature is 260°C for 10 seconds.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current sink during clamping | Connected to ground or low-impedance return path; forms low-inductance discharge loop with protected line. |
| Cathode | Protected line connection | Connected to the voltage rail or signal line requiring protection; polarity band identifies this terminal. |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power | Handles automotive load-dump surges (ISO 7637-2 Pulse 5a) without degradation when mounted per recommended footprint. |
| <1.0 ns response time | Clamps transients before propagation into IC inputs, reducing need for additional RC filtering on high-speed lines. |
| UL 497B recognition | Validates suitability for safety-critical isolated communication ports (e.g., RS-485, CAN FD physical layer) in certified equipment. |
| AEC-Q101 qualified (SZ variant) | Confirms reliability for automotive under-hood applications; 1SMB51AT3G shares identical electrical specs and package. |
| Low zener impedance | Maintains tight clamping voltage tolerance across temperature and aging, improving long-term protection consistency. |
Applications
| Automotive Power Distribution | Industrial DC Power Supply Rail |
|---|---|
Use Scenario: Protecting ECUs and body control modules from ISO 7637-2 load-dump transients on 12 V battery lines. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and local regulator input to clamp spikes to safe levels. Use Value: Limits voltage excursion to ≤82.4 V, preventing damage to 36 V-rated input stages of buck controllers and microcontrollers. |
Use Scenario: Safeguarding PLC I/O modules against switching surges from inductive loads on 24 V DC field buses. IC Role / Device Role / Timing Role: Parallel-connected TVS absorbing energy from relay coil flyback and contact arcing events. Use Value: Withstands 600 W pulses without failure, eliminating need for redundant protection or oversized heatsinking. |
| Medical Equipment Power Input | Telecom Isolated Data Interface |
Use Scenario: Shielding AC/DC adapter outputs and internal DC distribution rails in Class II medical devices. IC Role / Device Role / Timing Role: Primary overvoltage clamp on secondary-side 5 V/12 V rails feeding analog front-ends and digital logic. Use Value: UL 497B certification ensures compliance with patient-connected equipment isolation requirements and reduces safety testing burden. |
Use Scenario: Protecting RS-485 transceivers and isolated CAN nodes from ESD and surge coupling via shared ground paths. IC Role / Device Role / Timing Role: Bidirectional protection not required; unidirectional 1SMB51AT3G used on VCC side of isolated DC-DC converter output. Use Value: 16 kV HBM ESD rating and sub-ns response prevent latch-up in transceiver ICs during hot-plug or cable discharge events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ51A | Same VRWM (51 V) and VC (82.4 V), but lower peak power (400 W) and higher leakage (10 µA). | Limited to lower-energy transients; unsuitable for automotive load-dump or industrial motor drive environments. | Select only where cost sensitivity outweighs surge margin and leakage constraints. |
| SMCJ51A | Higher peak power (1500 W), same VRWM/VC, larger SMC package (7.11 × 6.22 mm vs. SMB 4.32 × 3.56 mm). | Requires PCB area increase and may introduce parasitic inductance due to longer trace routing in compact layouts. | Choose when system-level surge tests exceed 600 W or when extended lifetime under repetitive surges is required. |
Compared with SMAJ51A and SMCJ51A, the 1SMB51AT3G delivers optimal balance of surge robustness, compact SMB footprint, and low leakage - making it preferred for space-constrained automotive and industrial modules where 600 W peak handling suffices.
Availability
1SMB51AT3G is available at Aetrix Electronics and suitable for automotive electronic control units, industrial programmable logic controllers, medical power supplies, and telecom interface protection requiring stable component supply and full traceability.
Supply support for 1SMB51AT3G 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
ON Semiconductor (now onsemi) is a global semiconductor supplier specializing in power management, analog, sensor, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The SMB-series TVS diodes, including 1SMB51AT3G, were engineered for high-reliability transient suppression in harsh environments - emphasizing low clamping voltage, fast response, and regulatory compliance for safety-critical systems.
FAQ
What is the clamping voltage of the 1SMB51AT3G under standard surge conditions?
The 1SMB51AT3G clamps to a maximum of 82.4 V at 7.3 A peak pulse current (IPP), measured using the industry-standard 10/1000 µs double-exponential waveform. This value is guaranteed across temperature and process variation, ensuring consistent protection margin for downstream 36 V–60 V rated components in the 1SMB51AT3G application circuit.
Is the 1SMB51AT3G suitable for automotive applications?
Yes - while the base 1SMB51AT3G is not AEC-Q101 certified, its SZ-prefix variant (SZ1SMB51AT3G) is fully qualified to AEC-Q101 and PPAP capable. Both share identical electrical characteristics, SMB package, and thermal performance. For automotive designs, specify SZ1SMB51AT3G to meet qualification requirements without layout changes.
How does the 1SMB51AT3G differ from bidirectional TVS diodes?
The 1SMB51AT3G is unidirectional and functions only during positive transients on the cathode line relative to anode (ground). It cannot suppress negative-going surges - unlike bidirectional variants such as 1SMB51CAT3G. Use 1SMB51AT3G where polarity is fixed (e.g., DC power rails); select bidirectional types only for AC or floating signal lines.
What is the maximum allowable leakage current for the 1SMB51AT3G at its VRWM?
The 1SMB51AT3G guarantees a maximum reverse leakage current of 5.0 µA at its 51 V working peak reverse voltage (VRWM) and 25°C ambient temperature. At elevated temperatures (e.g., 85°C), leakage increases predictably but remains below 50 µA - critical for maintaining low quiescent power in always-on subsystems protected by the 1SMB51AT3G.
Does the 1SMB51AT3G require a heatsink for standard operation?
No - the 1SMB51AT3G is designed for surface-mount operation without external heatsinking. Its thermal resistance from junction-to-lead is 25 °C/W, and it dissipates only transient energy (non-repetitive). Continuous power dissipation is limited to 3.0 W at 75°C lead temperature, well within PCB copper pad thermal capacity when using ON Semiconductor's recommended footprint for Case 403A.
1SMB51AT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AA, SMB
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 82.4V
- Current - Peak Pulse (10/1000µs):
- 7.3A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- Telecom
- Capacitance @ Frequency:
- 345pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB51AT3G FAQ
1.How can I place an order for 1SMB51AT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB51AT3G 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 1SMB51AT3G reliable?
The price and inventory of 1SMB51AT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB51AT3G is usually 5 days.
3.What payment methods are accepted for 1SMB51AT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB51AT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB51AT3G?
1SMB51AT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB51AT3G 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 1SMB51AT3G?
For technical support, including 1SMB51AT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB51AT3G requirements.
6.How does Aetrix verify that 1SMB51AT3G is sourced from the original manufacturer or authorized distributors?
All 1SMB51AT3G 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 1SMB51AT3G meets industry standards.
7.What is the process for return or replacement of 1SMB51AT3G?
All 1SMB51AT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB51AT3G, 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 1SMB51AT3G part is unused and in its original packaging.
Return procedure for 1SMB51AT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB51AT3G Tags
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