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onsemi 1SMC51AT3G
- Part No.:
- 1SMC51AT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
1SMC51AT3G.pdf
- Description:
- TVS DIODE 51VWM 82.4VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:47,789
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Product details
Overview
1SMC51AT3G from onsemi is a unidirectional 1500 W peak power Zener transient voltage suppressor (TVS) designed for parallel clamping protection of DC power rails and signal lines. It features a 48 V working peak reverse voltage (VRWM), 56.7 V nominal breakdown voltage (VBR) at 1 mA, 82.4 V maximum clamping voltage (VC) at 18.2 A peak pulse current (IPP), and sub-1 ns response time. It is used in industrial power supplies to safeguard rectifier outputs and DC bus nodes against lightning-induced surges.
For engineers reviewing the 1SMC51AT3G datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage margin relative to protected IC VMAX, VRWM alignment with steady-state operating voltage, UL 497B certification for isolated loop compliance, and SMC package thermal performance under repetitive surge conditions.
Technical Context
The 1SMC51AT3G operates as a silicon avalanche diode configured in unidirectional Zener mode, triggered by reverse-biased overvoltage events exceeding its VBR threshold. Its low zener impedance (<1 Ω dynamic impedance near VBR) and fast carrier avalanche response enable effective suppression of 8/20 µs and 10/1000 µs transients without thermal runaway.
It is rated for 1500 W non-repetitive peak pulse power at 1 ms, with derating to 18.2 A IPP at TA = 25°C. The device exhibits <5 µA leakage above 10 V and a temperature coefficient of ±0.075%/°C, ensuring stable clamping across –65°C to +150°C operating range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 48 V - Maximum continuous reverse operating voltage before clamping begins; sets minimum system DC rail compatibility. |
| VBR @ IT=1 mA | 56.7 V (nominal) - Avalanche breakdown initiates within ±5% tolerance, defining precise overvoltage trip point. |
| VC @ IPP=18.2 A | 82.4 V - Maximum clamped voltage during 10/1000 µs surge; determines peak stress on downstream components. |
| PPK | 1500 W @ 1 ms - Peak transient energy handling capacity; validates suitability for IEC 61000-4-5 Level 4 surges. |
| Response Time | <1 ns - Enables clamping before most microsecond-scale transients fully develop; critical for protecting fast logic interfaces. |
| ESD Rating | Class 3 (>16 kV HBM) - Confirms robustness against human-body model electrostatic discharge in handling and assembly. |
| UL Recognition | UL 497B (QVGV2) - Certified for use in isolated loop circuit protection, including telecom and industrial fieldbus systems. |
Pinout & Package
1SMC51AT3G is housed in ON Semiconductor's Surmetic™ SMC (Case 403) surface-mount package: void-free thermosetting plastic body with modified L-bend leads, cathode indicated by molded notch, and RoHS-compliant finish. 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; carries full surge current during transient event. |
| Cathode | Protected line connection | Connected to the node requiring overvoltage protection (e.g., +48 V rail); polarity notch identifies this terminal. |
Key Features
| Feature | Design Value |
|---|---|
| 1500 W peak pulse power | Supports IEC 61000-4-5 surge immunity up to 4 kV (line-earth) without derating in standard PCB layouts. |
| Low clamping ratio (VC/VBR ≈ 1.46) | Minimizes overvoltage margin required between protected IC's absolute maximum rating and system operating voltage. |
| UL 497B recognition | Validates compliance for safety-critical isolated loop applications such as RS-485 fieldbus and PoE-powered devices. |
| Sub-1 ns response time | Reduces overshoot risk in high-speed power domains where layout inductance dominates transient behavior. |
| –65°C to +150°C operating range | Enables deployment in automotive engine compartments and industrial motor drive cabinets without thermal derating. |
Applications
| Industrial Power Supply Protection | Telecom DC Feeder Line Protection |
|---|---|
|
Use Scenario: Protecting 48 V DC output stage of AC/DC front-end converters against lightning-induced surges on long cable runs. IC Role / Device Role: Unidirectional parallel clamp placed between +48 V rail and chassis ground, absorbing >1 kA surge currents. Use Value: Limits rail voltage to ≤82.4 V during 10/1000 µs transients, preventing damage to downstream DC-DC controllers and MOSFET gate drivers. |
Use Scenario: Safeguarding central office line cards connected to outdoor copper loops exposed to induced surges. IC Role / Device Role: Primary overvoltage protector in UL 497B-compliant isolated loop interface, upstream of TPS6598x PMICs. Use Value: Meets Telcordia GR-1089-CORE requirements for longitudinal surge immunity while maintaining low standby leakage (<5 µA). |
| Automotive Body Control Module (BCM) | Medical Imaging Power Rail Clamping |
|
Use Scenario: Clamping 12 V battery rail transients caused by load dump or alternator switching in BCM ECU designs. IC Role / Device Role: Secondary TVS staged after primary LC filter, placed adjacent to MCU power pins per ISO 7637-2 Pulse 5a requirements. Use Value: Withstands 1500 W pulses at 125°C ambient, enabling compact placement near protected SoCs without thermal throttling. |
Use Scenario: Protecting high-voltage bias rails (e.g., 40–60 V) in X-ray detector analog front-ends from ESD and EFT events. IC Role / Device Role: Low-leakage transient suppressor on precision ADC reference supply, minimizing baseline drift during clamping. Use Value: <5 µA leakage at 10 V ensures <0.1% error contribution to 24-bit medical-grade SAR ADC references. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ51A | Same VRWM (48 V), lower PPK (600 W), SMB package (smaller footprint, higher RJA). | Limited to lower-energy transients (IEC 61000-4-5 Level 2); unsuitable for long-line telecom feeder protection. | Select when board space is constrained and surge threat level is defined as <1 kV line-earth. |
| 1.5SMC51A | Identical electrical specs but obsolete marking suffix; same SMC package and UL 497B recognition. | No functional difference; legacy part number with identical qualification and traceability. | Prefer 1SMC51AT3G for new designs due to active manufacturing status and tape-and-reel packaging (2500/reel). |
Compared with SMBJ51A, 1SMC51AT3G delivers 2.5× higher surge energy handling and superior thermal dissipation in the larger SMC case; versus 1.5SMC51A, it offers updated process control and guaranteed availability through ON Semiconductor's preferred-device program.
Availability
1SMC51AT3G is available at Aetrix Electronics and suitable for industrial power supplies, telecom infrastructure equipment, and automotive electronic control units requiring stable component supply and certified surge protection.
Supply support for 1SMC51AT3G 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 delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The 1SMC51AT3G belongs to the SMC-series unidirectional TVS family, engineered specifically for high-reliability, high-energy transient suppression in harsh-environment power electronics where UL 497B compliance and 1500 W surge capability are mandatory.
FAQ
What is the clamping voltage of the 1SMC51AT3G at its rated peak pulse current?
The 1SMC51AT3G has a maximum clamping voltage (VC) of 82.4 V at its rated peak pulse current (IPP) of 18.2 A under 10/1000 µs waveform conditions. This value is measured per JEDEC standards and defines the upper voltage limit imposed on protected circuits during worst-case surge events, ensuring downstream components remain within safe operating limits.
Is the 1SMC51AT3G suitable for bidirectional transient suppression?
No, the 1SMC51AT3G is a unidirectional TVS diode and must be used with correct polarity-cathode connected to the protected line, anode to ground. It does not suppress positive transients on the anode side. For bidirectional protection, a separate device such as the 1SMC51AT3G's complementary series (not offered in SMC) or a dedicated bidirectional TVS like SMAJ51A would be required.
Does the 1SMC51AT3G meet UL 497B certification requirements?
Yes, the 1SMC51AT3G is UL Recognized under file QVGV2 to UL 497B for isolated loop circuit protection. This certification covers performance validation across strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge testing-making it suitable for telecom, industrial fieldbus, and medical isolation barrier applications where regulatory compliance is mandatory.
What is the thermal resistance from junction to ambient for the 1SMC51AT3G?
The 1SMC51AT3G has a thermal resistance from junction to ambient (RJA) of 165°C/W when mounted on an FR-4 board using ON Semiconductor's recommended minimum footprint (Case 403 outline). This value assumes no additional copper pour; adding thermal pads or internal planes reduces RJA significantly and is recommended for high-duty-cycle surge environments.
How does the 1SMC51AT3G compare to the older 1.5SMC51A in terms of reliability and availability?
The 1SMC51AT3G supersedes the 1.5SMC51A with identical electrical specifications and UL 497B recognition but benefits from updated wafer fabrication controls, enhanced surge test screening, and active inclusion in onsemi's Preferred Devices program. Unlike the legacy 1.5SMC51A, the 1SMC51AT3G is supported with full production continuity and tape-and-reel packaging (2500/reel), ensuring long-term supply stability for new designs.
1SMC51AT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AB, SMC
- 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):
- 18.2A
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMC
1SMC51AT3G FAQ
1.How can I place an order for 1SMC51AT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMC51AT3G 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 1SMC51AT3G reliable?
The price and inventory of 1SMC51AT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMC51AT3G is usually 5 days.
3.What payment methods are accepted for 1SMC51AT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMC51AT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMC51AT3G?
1SMC51AT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMC51AT3G 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 1SMC51AT3G?
For technical support, including 1SMC51AT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMC51AT3G requirements.
6.How does Aetrix verify that 1SMC51AT3G is sourced from the original manufacturer or authorized distributors?
All 1SMC51AT3G 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 1SMC51AT3G meets industry standards.
7.What is the process for return or replacement of 1SMC51AT3G?
All 1SMC51AT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMC51AT3G, 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 1SMC51AT3G part is unused and in its original packaging.
Return procedure for 1SMC51AT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMC51AT3G Tags
-
ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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ESD5Z3.3T1G
onsemi
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D5V0H1B2LP-7B
Diodes Incorporated
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D5V0P1B2LP-7B
Diodes Incorporated
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DESD5V0U1BA-7
Diodes Incorporated
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ESD5Z5.0T1G
onsemi
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DESD5V0U1BB-7
Diodes Incorporated
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D12V0L1B2LP-7B
Diodes Incorporated
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PESD2V0Y1BSFYL
Nexperia USA Inc.
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DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
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D5V0L1B2WS-7
Diodes Incorporated
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