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onsemi 1SMB51AT3
- Part No.:
- 1SMB51AT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB51AT3.pdf
- Description:
- TVS DIODE 51VWM 82.4VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:9,479
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Product details
Overview
1SMB51AT3 from ON Semiconductor is a unidirectional 600 W peak power Zener transient voltage suppressor (TVS) designed for parallel overvoltage protection of sensitive electronics. It features a 51 V working peak reverse voltage (VRWM), 56.7 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 protecting DC power rails in industrial power supplies and automotive control modules.
For engineers reviewing the 1SMB51AT3 datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage margin relative to system operating voltage, surge current handling under 10/1000 µs transients, UL 497B recognition for isolated loop protection, and SMB package thermal performance in high-density PCB layouts.
Technical Context
This device operates as a voltage-clamping Zener diode in avalanche breakdown mode during transient events. Its response time is typically under 1.0 ns, and it maintains low zener impedance to ensure rapid voltage stabilization during ESD or lightning-induced surges.
The 1SMB51AT3 is rated for 600 W peak pulse power (10/1000 µs waveform), supports 100 A non-repetitive forward surge current, and exhibits <5.0 µA reverse leakage at VRWM - critical for low-power standby circuits where leakage must not disrupt bias networks.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 51 V - maximum continuous reverse operating voltage before clamping begins; sets minimum system rail voltage compatibility. |
| VBR (min/typ/max) | 53.3 V / 56.7 V / 59.7 V @ 1 mA - defines precise avalanche onset; ensures predictable turn-on across temperature and unit variation. |
| VC @ IPP | 82.4 V @ 7.3 A - clamping voltage under standardized 10/1000 µs surge; determines maximum stress on downstream ICs. |
| Peak Pulse Power | 600 W @ 1 ms - energy-handling capability for single-event transients; validated per IEC 61000-4-5 Level 4 compliance paths. |
| Leakage Current | <5.0 µA @ 51 V - negligible standby current draw; avoids loading of high-impedance sensor references or battery-backed circuits. |
| Capacitance | 345 pF @ 0 V - limits high-frequency signal distortion; acceptable for DC/low-speed digital lines but unsuitable for USB or HDMI interfaces. |
| ESD Rating | Class 3 (>16 kV HBM) - exceeds IEC 61000-4-2 Level 4; provides robust handling during board assembly and field service. |
Pinout & Package
Package: SMB (Case 403A), surface-mount, 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 entry terminal during forward conduction or transient clamp | Connected to system ground or lower-potential node; forms return path during surge dissipation. |
| Cathode | Current exit terminal during reverse-biased clamping | Connected to protected line (e.g., +51 V rail); voltage referenced to anode during avalanche operation. |
Key Features
| Feature | Design Value |
|---|---|
| UL 497B Recognition (QVGQ2) | Validated for isolated loop circuit protection - enables use in telecom interface cards without additional safety certification effort. |
| AEC-Q101 Qualified (SZ variant) | Qualified for automotive underhood applications - supports deployment in engine control units and ADAS power domains. |
| Surmet™ Package | ON Semiconductor's proprietary molded plastic housing - delivers superior moisture resistance and thermal cycling reliability vs. standard SMB. |
| Low Clamping Ratio (VC/VBR) | 1.45 (82.4 V / 56.7 V) - tight voltage margin between breakdown and clamping ensures minimal overvoltage exposure to protected ICs. |
| Pb-Free Construction | RoHS-compliant termination finish - meets IPC-J-STD-020 reflow profiles and eliminates lead-based solder compatibility concerns. |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module |
|---|---|
|
Use Scenario: Protects 48 V DC input stage of programmable logic controller (PLC) power supply against load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Unidirectional TVS placed directly across input terminals to shunt surge energy to ground before reaching upstream rectifier and bulk capacitor. Use Value: Clamps 500 V/100 A transients to ≤82.4 V within 1 ns, preventing MOSFET gate oxide rupture and maintaining regulation integrity. |
Use Scenario: Safeguards LIN bus transceiver power pins in door module against battery reverse connection and jump-start spikes. IC Role / Device Role / Timing Role: Standoff device mounted adjacent to transceiver VCC pin to clamp reverse polarity and load dump events before internal LDO fails. Use Value: Withstands 100 A forward surge (8.3 ms half-sine) and maintains <5 µA leakage at 13.5 V, avoiding false wake-up in sleep mode. |
| Medical Equipment Input Stage | Telecom Isolated Data Interface |
|
Use Scenario: Shields AC/DC adapter secondary-side output against ESD and fast transient bursts in patient monitor auxiliary power rails. IC Role / Device Role / Timing Role: Final-stage overvoltage guard on 24 V output, positioned after filtering to prevent coupling of clamp noise into analog front-end. Use Value: UL 497B recognition confirms suitability for medically isolated circuits; 345 pF capacitance avoids signal integrity issues on low-bandwidth sensor buses. |
Use Scenario: Protects RS-485 transceiver VCC and GND pins in isolated repeater nodes subjected to induced surges on long cable runs. IC Role / Device Role / Timing Role: Dual placement - one device across VCC-GND, another across data pair - to suppress common-mode and differential transients. Use Value: 600 W rating handles multi-kV surges per IEC 61000-4-5; bidirectional variants exist, but this unidirectional version optimizes cost where polarity is controlled. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SZ1SMB51AT3G | AEC-Q101 qualified, automotive-grade variant with identical electrical specs and Pb-free packaging. | Required for automotive OEM designs needing PPAP documentation and extended temperature validation (−40°C to +125°C). | Select SZ1SMB51AT3G when automotive qualification, traceability, or enhanced process controls are mandatory. |
| 1SMB51AHE3/73 | Vishay part with same SMB package, 51 V VRWM, and 82.4 V VC, but rated for 600 W with different derating curve and no UL 497B listing. | Lacks UL recognition; suitable for non-safety-critical industrial equipment where certification overhead must be minimized. | Choose 1SMB51AHE3/73 only if UL 497B is not required and Vishay supply chain alignment is preferred. |
Compared with 1SMB51AT3, SZ1SMB51AT3G adds automotive qualification and process rigor without altering clamping behavior, while 1SMB51AHE3/73 offers functional equivalence in non-certified systems but requires independent safety validation.
Availability
1SMB51AT3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, medical equipment input stages, and telecom isolated data interfaces requiring stable component supply across multi-year production cycles.
Supply support for 1SMB51AT3 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, sensors, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The SMB-series TVS diodes, including 1SMB51AT3, were developed to deliver high-energy transient suppression in compact surface-mount packages for space-constrained, high-reliability applications across transportation and medical sectors.
FAQ
What is the clamping voltage of the 1SMB51AT3 under a 10/1000 µs surge?
The 1SMB51AT3 clamps to a maximum of 82.4 V when subjected to a 7.3 A peak pulse current (IPP), which corresponds to the standardized 10/1000 µs double-exponential surge waveform. This value is measured at TA = 25°C and defines the upper voltage limit imposed on protected circuitry during transient events. The 1SMB51AT3 achieves this clamping performance while maintaining low dynamic impedance, ensuring consistent protection across production lots.
Is the 1SMB51AT3 RoHS compliant and lead-free?
Yes, the 1SMB51AT3 is manufactured in a Pb-free configuration using ON Semiconductor's Surmetic™ package technology. It complies with RoHS Directive 2011/65/EU and meets JEDEC J-STD-020 moisture sensitivity level (MSL) requirements. The device supports standard reflow profiles up to 260°C for 10 seconds, and its terminations are compatible with both leaded and lead-free soldering processes without degradation of surge performance.
Does the 1SMB51AT3 have UL recognition for safety-critical applications?
Yes, the 1SMB51AT3 carries UL 497B recognition under file E210057 for protector classification (QVGQ2). This certification validates its performance in isolated loop circuit protection, including passing strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge tests. UL 497B approval makes the 1SMB51AT3 suitable for use in telecom interface cards, medical isolation barriers, and industrial control systems requiring third-party safety validation.
How does the 1SMB51AT3 differ from the SZ1SMB51AT3G variant?
The SZ1SMB51AT3G is the automotive-qualified version of the 1SMB51AT3, fully AEC-Q101 certified and PPAP-capable. Both share identical electrical specifications, SMB package dimensions, and clamping characteristics. However, the SZ prefix indicates enhanced process controls, extended temperature validation (−40°C to +125°C), and full automotive traceability documentation - requirements essential for engine control units, ADAS modules, and other vehicle subsystems where failure modes carry higher risk.
What is the maximum reverse leakage current of the 1SMB51AT3 at its rated VRWM?
The 1SMB51AT3 exhibits a maximum reverse leakage current of 5.0 µA when biased at its working peak reverse voltage of 51 V and measured at 25°C. This ultra-low leakage ensures minimal power loss in always-on circuits and prevents unintended discharge of hold-up capacitors in backup power systems. The specification is guaranteed across the full operating temperature range (−65°C to +150°C), with typical leakage remaining below 1 µA at room temperature.
1SMB51AT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AA, SMB
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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:
- General Purpose
- Capacitance @ Frequency:
- 345pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB51AT3 FAQ
1.How can I place an order for 1SMB51AT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB51AT3 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 1SMB51AT3 reliable?
The price and inventory of 1SMB51AT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB51AT3 is usually 5 days.
3.What payment methods are accepted for 1SMB51AT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB51AT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB51AT3?
1SMB51AT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB51AT3 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 1SMB51AT3?
For technical support, including 1SMB51AT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB51AT3 requirements.
6.How does Aetrix verify that 1SMB51AT3 is sourced from the original manufacturer or authorized distributors?
All 1SMB51AT3 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 1SMB51AT3 meets industry standards.
7.What is the process for return or replacement of 1SMB51AT3?
All 1SMB51AT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB51AT3, 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 1SMB51AT3 part is unused and in its original packaging.
Return procedure for 1SMB51AT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB51AT3 Tags
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onsemi
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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