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onsemi 1SMC51AT3
- Part No.:
- 1SMC51AT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- -
- Datasheet:
-
1SMC51AT3.pdf
- Description:
- TVS DIODE 51V 82.4V SMC
- Quantity:
- Payment:
- Shipping:
Inventory:7,547
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Product details
Overview
1SMC51AT3 from ON Semiconductor is a unidirectional 1500 W peak power Zener transient voltage suppressor (TVS) designed for parallel clamping protection of sensitive electronics against ESD, lightning-induced surges, and inductive switching transients. It features a 51 V working peak reverse voltage (VRWM), 59.7 V nominal breakdown voltage (VBR) at 1 A test current, 82.4 V maximum clamping voltage (VC) at 18.2 A peak pulse current, and sub-1 ns response time - deployed in power supplies, industrial controls, and automotive ECUs.
For engineers reviewing the 1SMC51AT3 datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage margin relative to protected circuit's max operating voltage, surge current handling under 1 ms 10/1000 µs waveform, UL 497B certification for isolated loop protection, and SMC package thermal performance at 75 °C lead temperature.
Technical Context
This TVS diode operates as a voltage-clamped shunt protector: under normal bias it presents <5 µA leakage above VRWM; when transient voltage exceeds VBR, it avalanches into low-impedance conduction, limiting voltage across the load to ≤82.4 V at 18.2 A. Its design targets single-pulse, non-repetitive surge events per IEC 61000-4-5 Level 4 (4 kV/2 Ω) and ESD per HBM Class 3 (>16 kV).
The device uses a planar Zener junction in an SMC (DO-214AB) surface-mount package with modified L-bend leads, enabling high thermal dissipation (RJL = 54.6 °C/W) and robust 200 A forward surge capability. Polarity is marked by a molded cathode notch, and Pb-free construction complies with RoHS and JESD204B reflow profiles.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 51 V - Maximum continuous reverse operating voltage before clamping begins; sets minimum system voltage margin. |
| VBR @ IT=1 A | 59.7 V (nominal) - Breakdown threshold where avalanche conduction initiates; defines turn-on sensitivity. |
| VC @ IPP=18.2 A | 82.4 V - Clamped voltage during 1 ms 10/1000 µs surge; must stay below protected IC's absolute max rating. |
| PPK | 1500 W - Peak pulse power handling at TL=25 °C; derates to 750 W at TL=75 °C per datasheet curve. |
| Response Time | <1 ns - Time from transient onset to clamping onset; critical for protecting fast logic and data lines. |
| Leakage Current | <5 µA @ 51 V - Ensures minimal standby power loss and no false triggering in DC-biased circuits. |
| UL Recognition | UL 497B QVGQ2 - Certified for isolated loop circuit protection; validates reliability in telecom and industrial interfaces. |
Pinout & Package
The 1SMC51AT3 is housed in an SMC (DO-214AB) plastic surface-mount package (Case 403), measuring 5.59–6.10 mm × 6.60–7.11 mm × 1.90–2.41 mm (L×W×H), with cathode polarity indicated by a molded notch on the case body. Leads are modified L-bend for enhanced pad contact area and solderability.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to circuit ground or lowest potential node; completes clamping path during transient. |
| Cathode | High-side surge input terminal | Connected to protected line (e.g., +51 V rail); voltage referenced to anode determines clamping behavior. |
Key Features
| Feature | Design Value |
|---|---|
| 1500 W peak pulse power | Handles IEC 61000-4-5 Level 4 surges (4 kV/2 Ω) without degradation when mounted per recommended footprint. |
| UL 497B certified | Validated for isolated loop protection in telecom and industrial interfaces - exceeds basic flammability requirements. |
| ESD rating >16 kV HBM | Protects downstream components from human-body-model electrostatic discharge without external series impedance. |
| Low zener impedance | Ensures tight clamping voltage control (<3% variation over rated IPP) and stable suppression across temperature. |
| Pb-free SURMETIC™ package | RoHS-compliant thermosetting plastic housing with corrosion-resistant, solderable leads and 260 °C/10 s reflow tolerance. |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module |
|---|---|
Use Scenario: 48 V–60 V DC input stage of programmable logic controller (PLC) power supply exposed to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Shunt clamping TVS placed directly across input capacitor to limit transient voltage to <85 V during 100 ms load dump events. Use Value: Prevents overvoltage failure of upstream buck controller and downstream 3.3 V/5 V regulators by clamping within 1 ns to 82.4 V at 18.2 A. |
Use Scenario: CAN bus physical layer interface in vehicle door module subjected to ESD and battery reversal transients. IC Role / Device Role / Timing Role: Unidirectional TVS connected between CAN_H and ground to clamp common-mode surges while preserving signal integrity. Use Value: Maintains CAN FD communication up to 5 Mbps by limiting overshoot to ≤82.4 V without adding capacitive loading beyond 50 pF. |
| Medical Imaging Power Rail | Telecom Isolated Data Interface |
Use Scenario: High-voltage X-ray generator auxiliary supply rail (51 V ±5%) requiring immunity to 1 kV/500 Ω ring wave transients per IEC 61000-4-12. IC Role / Device Role / Timing Role: Primary overvoltage clamp on secondary-side 51 V output, coordinated with upstream fuse and MOV. Use Value: Limits transient excursion to 82.4 V for <1 ms, preventing latch-up in FPGA-based timing controllers and analog front-end ASICs. |
Use Scenario: RS-485 transceiver side of galvanically isolated industrial Ethernet gateway with UL 497B-compliant barrier. IC Role / Device Role / Timing Role: UL 497B-recognized TVS on isolated 51 V bias rail feeding isolated DC-DC converter for RS-485 PHY. Use Value: Enables UL listing of full system by meeting strike voltage breakdown and endurance conditioning requirements for protector-class devices. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SZ1SMC51AT3G | Automotive-grade variant with AEC-Q101 qualification, PPAP capability, and tighter VBR tolerance (±5% vs ±10% standard). | Required for automotive ECUs subject to OEM PPAP; not needed for industrial or medical non-automotive use. | Select SZ1SMC51AT3G only if AEC-Q101 compliance and production traceability are mandated. |
| 1.5SMC51A | Same electrical specs but in legacy SMC package with different marking and obsolete packaging (no G-suffix; tape/reel count differs). | No functional difference; used where legacy BOMs or distributor stock require non-Pb-free version. | Choose 1.5SMC51A only for backward compatibility with pre-2010 designs or inventory reuse; 1SMC51AT3 offers improved manufacturability. |
Compared with SZ1SMC51AT3G and 1.5SMC51A, the 1SMC51AT3 provides optimal balance of RoHS compliance, UL 497B certification, and cost-effective SMC packaging - making it preferred for new industrial and medical designs where automotive qualification is unnecessary and Pb-free assembly is required.
Availability
1SMC51AT3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, and medical imaging equipment requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for 1SMC51AT3 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 is a global semiconductor manufacturer specializing in power management, analog, sensor, and discrete solutions for automotive, industrial, and cloud power applications.
The 1SMC51AT3 belongs to ON Semiconductor's SMC-series Zener TVS family, engineered specifically for high-energy transient suppression in harsh environments where reliability, UL certification, and fast response are critical.
FAQ
What is the clamping voltage of the 1SMC51AT3 under a 1 ms surge?
The 1SMC51AT3 clamps to a maximum of 82.4 V when subjected to its rated peak pulse current of 18.2 A under a 1 ms 10/1000 µs waveform. This value is measured per Figure 2 in the official ON Semiconductor datasheet and represents the upper bound of voltage seen by protected circuitry during worst-case surge conditions.
Is the 1SMC51AT3 RoHS compliant and Pb-free?
Yes, the 1SMC51AT3 is Pb-free and RoHS compliant, manufactured in ON Semiconductor's SURMETIC™ package using lead-free molding compound and terminations. It meets JEDEC J-STD-020 reflow profiles and supports 260 °C/10 s soldering per datasheet specifications.
Does the 1SMC51AT3 have UL 497B recognition?
Yes, the 1SMC51AT3 carries UL 497B recognition under file #E210057 in the "Protector" category (QVGQ2), validating its suitability for isolated loop circuit protection in telecom and industrial systems - a certification many competing TVS diodes lack entirely.
What is the thermal resistance from junction-to-lead for the 1SMC51AT3?
The 1SMC51AT3 has a thermal resistance from junction-to-lead (RJL) of 54.6 °C/W when mounted on a 1 in² copper pad on FR-4 board. This parameter governs power derating above 75 °C lead temperature and informs heatsinking decisions in high-duty-cycle applications.
How does the 1SMC51AT3 differ from the SZ1SMC51AT3G variant?
The 1SMC51AT3 is the commercial-grade version, while the SZ1SMC51AT3G adds AEC-Q101 qualification, PPAP capability, and tighter process controls for automotive use. Both share identical electrical specs and SMC packaging, but only the SZ-prefix part meets OEM automotive quality and documentation requirements.
1SMC51AT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- -
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- -
- Unidirectional Channels:
- -
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- -
- Voltage - Breakdown (Min):
- -
- Voltage - Clamping (Max) @ Ipp:
- -
- Current - Peak Pulse (10/1000µs):
- -
- Power - Peak Pulse:
- -
- Power Line Protection:
- -
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
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1SMC51AT3 FAQ
1.How can I place an order for 1SMC51AT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMC51AT3 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 1SMC51AT3 reliable?
The price and inventory of 1SMC51AT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMC51AT3 is usually 5 days.
3.What payment methods are accepted for 1SMC51AT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMC51AT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMC51AT3?
1SMC51AT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMC51AT3 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 1SMC51AT3?
For technical support, including 1SMC51AT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMC51AT3 requirements.
6.How does Aetrix verify that 1SMC51AT3 is sourced from the original manufacturer or authorized distributors?
All 1SMC51AT3 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 1SMC51AT3 meets industry standards.
7.What is the process for return or replacement of 1SMC51AT3?
All 1SMC51AT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMC51AT3, 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 1SMC51AT3 part is unused and in its original packaging.
Return procedure for 1SMC51AT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMC51AT3 Tags
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