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onsemi 1.5SMC51AT3
- Part No.:
- 1.5SMC51AT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
1.5SMC51AT3.pdf
- Description:
- TVS DIODE 43.6VWM 70.1VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:2,097
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Product details
Overview
1.5SMC51AT3 from ON Semiconductor is a unidirectional 1500 W peak power Zener transient voltage suppressor (TVS) designed for parallel overvoltage protection of sensitive electronics. It features a 43.6 V working peak reverse voltage (VRWM), 51 V breakdown voltage (VBR) at 1 mA test current, clamps to 70.1 V at 21.4 A peak pulse current, and responds in under 1 ns. It is used in industrial power supplies, automotive ECUs, and communication interface circuits to absorb lightning-induced surges and ESD events.
For engineers reviewing the 1.5SMC51AT3 datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage margin vs. system operating voltage, peak pulse current capability under 1 ms waveform, UL 497B certification for isolated loop protection, and SMC package thermal performance on FR-4 PCBs.
Technical Context
The 1.5SMC51AT3 operates as a unidirectional Zener-based TVS diode, conducting only in reverse bias above its breakdown threshold. Its low zener impedance and fast <1 ns response enable effective clamping of high-energy transients without significant overshoot when properly laid out.
It is rated for 1500 W non-repetitive peak power per 10/1000 µs waveform, with thermal derating starting at 75°C junction temperature. The device meets UL 497B for isolated loop circuit protection and exhibits Class 3 ESD immunity (>16 kV HBM).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 1500 W @ 1 ms, supports robust surge immunity per IEC 61000-4-5 Level 4 |
| Working Peak Reverse Voltage (VRWM) | 43.6 V - maximum continuous reverse voltage before clamping begins |
| Breakdown Voltage (VBR) | 51 V @ 1 mA - precise Zener conduction onset for predictable protection threshold |
| Clamping Voltage (VC) | 70.1 V @ 21.4 A IPP - limits protected circuit voltage during surge |
| Leakage Current (IR) | <5 µA @ 43.6 V - minimal standby power loss and signal integrity impact |
| Response Time | <1 ns - ensures clamping activation before transient energy damages downstream ICs |
| ESD Rating | Class 3 (>16 kV HBM) - exceeds IEC 61000-4-2 Level 4 for system-level ESD robustness |
Pinout & Package
1.5SMC51AT3 is housed in an SMC (DO-214AB) surface-mount plastic package (Case 403), featuring a modified L-bend lead form for enhanced solder joint reliability and thermal transfer. Polarity is marked by a molded cathode notch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side reference | Connected to ground or lowest potential node in unidirectional clamp configuration |
| Cathode | Zener avalanche terminal / high-side input | Connected to protected line (e.g., DC bus, data line) to shunt surge current to ground |
Key Features
| Feature | Design Value |
|---|---|
| UL 497B Recognition | Qualified for isolated loop circuit protection - enables use in telecom and industrial safety-critical interfaces without additional certification burden |
| Low Clamping Ratio (VC/VBR) | 1.37 - tight voltage margin between breakdown and clamping improves system headroom and reduces stress on downstream components |
| Thermal Resistance (RJL) | 54.6 °C/W - enables 4.0 W DC dissipation at 75°C lead temperature, supporting sustained surge duty in compact layouts |
| Surmetic™ Package | Void-free, corrosion-resistant thermoset molding - ensures long-term reliability in humid or chemically aggressive environments |
| 100% Lead Finish Solderability | RoHS-compliant matte tin plating - guarantees consistent wetting and joint integrity during reflow assembly |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: Protecting 48 V DC input rails in programmable logic controllers against load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Unidirectional TVS placed across input terminals to clamp transients before they reach DC-DC converters and microcontrollers. Use Value: 70.1 V clamping voltage provides 22 V margin above 48 V nominal rail, preventing overvoltage damage while maintaining compatibility with standard 75 V-rated components. |
Use Scenario: Safeguarding LIN bus lines and sensor inputs in BCMs exposed to battery transients and ESD. IC Role / Device Role / Timing Role: Parallel-connected TVS on each LIN line to limit voltage excursions during ignition switching and human contact events. Use Value: Class 3 ESD rating and sub-1 ns response ensure reliable operation in vehicle cabin environments where >15 kV ESD is common. |
| Telecom Interface Protection | Medical Equipment Power Input |
Use Scenario: Shielding RS-485 transceivers and Ethernet PHYs in base station backhaul units from induced lightning surges. IC Role / Device Role / Timing Role: Primary surge suppression stage ahead of secondary filtering and isolation barriers. Use Value: 1500 W peak power rating meets IEC 61000-4-5 Combination Wave (10/700 µs) requirements for outdoor telecom infrastructure. |
Use Scenario: Protecting AC/DC front-end rectifiers and PFC stages in diagnostic imaging equipment from mains-borne surges. IC Role / Device Role / Timing Role: First-line transient suppressor on primary-side DC bus after bridge rectifier. Use Value: UL 497B recognition validates suitability for patient-connected medical devices requiring certified isolation barrier protection. |
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 (43.6 V) and VBR (51 V), but lower 600 W peak power rating | Suitable for lower-energy transients (IEC 61000-4-2, not 4-5); smaller SMB package limits thermal mass | Select when board space is constrained and surge threat level is limited to ESD and minor switching noise |
| 1.5KE51A | Through-hole TO-204AA (DO-41) package; identical electrical specs but higher thermal resistance (RJA = 200 °C/W) | Requires larger PCB footprint and manual or wave soldering; less suitable for high-density automated assembly | Choose for legacy designs, prototyping, or applications where mechanical robustness outweighs SMT density requirements |
Compared with SMBJ51A and 1.5KE51A, the 1.5SMC51AT3 delivers full 1500 W surge handling in a compact SMC package with superior thermal performance (RJL = 54.6 °C/W), making it optimal for high-reliability, high-density industrial and automotive power systems requiring UL 497B compliance.
Availability
1.5SMC51AT3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive control modules, telecom interface protection, and medical equipment power inputs requiring stable component supply and long-term lifecycle support.
Supply support for 1.5SMC51AT3 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 energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The 1.5SMC51AT3 belongs to ON Semiconductor's SMC-series transient voltage suppressors - engineered for high-surge industrial and automotive applications where reliability, UL certification, and precise clamping performance are critical.
FAQ
What is the clamping voltage of the 1.5SMC51AT3 and how is it measured?
The 1.5SMC51AT3 has a maximum clamping voltage (VC) of 70.1 V, measured at a peak pulse current (IPP) of 21.4 A using a 10/1000 µs double-exponential waveform. This value represents the highest voltage the device allows across its terminals during a standardized surge event, ensuring downstream components remain within safe operating limits. The 1.5SMC51AT3 achieves this clamping performance consistently due to its low dynamic impedance and optimized Zener structure.
Is the 1.5SMC51AT3 RoHS compliant and halogen-free?
Yes, the 1.5SMC51AT3 is RoHS compliant and halogen-free per ON Semiconductor's product specifications and material declarations. Its Surmetic™ package uses lead-free matte tin plating on leads and halogen-free epoxy molding compound, meeting JEDEC J-STD-609 Category 1 requirements. This ensures environmental compliance and solderability in modern lead-free reflow processes without compromising surge robustness.
Can the 1.5SMC51AT3 be used in bidirectional protection circuits?
No, the 1.5SMC51AT3 is a unidirectional TVS diode and is not suitable for bidirectional protection. Its design conducts only in reverse bias above 51 V breakdown, with forward conduction limited to ~3.5 V. For AC or bipolar signal lines (e.g., USB, RS-485), a dedicated bidirectional part such as SMBJ51CA must be selected - the 1.5SMC51AT3 would fail to protect during negative-going transients.
What is the thermal derating behavior of the 1.5SMC51AT3 above 75°C?
The 1.5SMC51AT3 derates linearly above 75°C lead temperature at 18.3 mW/°C, reducing its DC power dissipation capability from 4.0 W at 75°C to zero at approximately 297°C. For pulsed operation, ambient temperature derating follows Figure 3 in the datasheet: at 125°C ambient, peak pulse power drops to ~60% of the 1500 W rating. Proper copper pad area and airflow are essential to maintain thermal performance in high-temperature enclosures.
Does the 1.5SMC51AT3 require external series impedance for proper operation?
Yes, the 1.5SMC51AT3 requires external series impedance (e.g., fuse, resistor, or ferrite bead) between the protected line and the TVS to limit fault current during sustained overvoltage conditions. Without it, continuous conduction above VRWM could cause thermal runaway. The recommended Zin value balances protection speed and device survivability - typically 1–10 Ω for power rails and ≥100 Ω for signal lines - ensuring the 1.5SMC51AT3 clamps effectively without overstress.
1.5SMC51AT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AB, SMC
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 43.6V
- Voltage - Breakdown (Min):
- 48.5V
- Voltage - Clamping (Max) @ Ipp:
- 70.1V
- Current - Peak Pulse (10/1000µs):
- 21.4A
- 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
1.5SMC51AT3 FAQ
1.How can I place an order for 1.5SMC51AT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1.5SMC51AT3 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 1.5SMC51AT3 reliable?
The price and inventory of 1.5SMC51AT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1.5SMC51AT3 is usually 5 days.
3.What payment methods are accepted for 1.5SMC51AT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1.5SMC51AT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1.5SMC51AT3?
1.5SMC51AT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1.5SMC51AT3 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 1.5SMC51AT3?
For technical support, including 1.5SMC51AT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1.5SMC51AT3 requirements.
6.How does Aetrix verify that 1.5SMC51AT3 is sourced from the original manufacturer or authorized distributors?
All 1.5SMC51AT3 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 1.5SMC51AT3 meets industry standards.
7.What is the process for return or replacement of 1.5SMC51AT3?
All 1.5SMC51AT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1.5SMC51AT3, 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 1.5SMC51AT3 part is unused and in its original packaging.
Return procedure for 1.5SMC51AT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1.5SMC51AT3 Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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onsemi
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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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Toshiba Semiconductor and Storage
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Diodes Incorporated
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