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onsemi 1SMC40AT3
- Part No.:
- 1SMC40AT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- -
- Datasheet:
-
1SMC40AT3.pdf
- Description:
- TVS 1500W 40V UNIDIRECT SMC
- Quantity:
- Payment:
- Shipping:
Inventory:9,987
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Product details
Overview
1SMC40AT3 from ON Semiconductor is a unidirectional 1500 W transient voltage suppressor (TVS) diode designed for primary overvoltage protection in DC power rails and signal lines. It features a 40 V working peak reverse voltage (VRWM), 49.1 V nominal breakdown voltage (VBR) at 1 A, clamps to ≤64.5 V at 32.2 A peak pulse current, and responds in <1 ns. It is used in industrial power supplies to protect downstream regulators and microcontrollers from lightning-induced surges.
For engineers reviewing the 1SMC40AT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system operating voltage, clamping voltage margin relative to IC absolute maximum ratings, UL 497B recognition for isolated loop compliance, and SMC package thermal performance under repetitive surge conditions.
Technical Context
The 1SMC40AT3 operates as a Zener-based avalanche clamp, conducting only when reverse voltage exceeds its specified breakdown threshold. Its unidirectional polarity requires cathode connection to the protected line and anode to ground, enabling precise DC rail protection without forward conduction during normal operation.
It delivers 1500 W peak pulse power per 1 ms 10/1000 µs waveform, with thermal resistance of 165 °C/W junction-to-ambient on FR-4 board and 54.6 °C/W junction-to-lead on 1 in² copper pad. Leakage remains <5 µA above 10 V, ensuring minimal standby power loss in always-on systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 40 V - Maximum continuous reverse voltage before clamping begins; must exceed system DC operating voltage. |
| VBR (min/typ/max) | 44.2 / 46.75 / 49.1 V @ 1 A - Ensures reliable turn-on within defined tolerance band across temperature and production lot. |
| VC @ IPP | 64.5 V @ 32.2 A - Clamping voltage under full-rated surge; determines maximum stress on protected ICs. |
| PPK | 1500 W @ 1 ms - Peak energy absorption capability for transient suppression per IEC 61000-4-5 Level 4. |
| IR @ VRWM | ≤5 µA - Low leakage preserves efficiency in high-impedance sensing or battery-backed circuits. |
| Response Time | <1 ns - Fast enough to limit overshoot before sensitive logic or analog circuitry is damaged. |
| UL Recognition | UL 497B QVGQ2 - Certified for use in isolated loop telecom and industrial control protection circuits. |
Pinout & Package
1SMC40AT3 is housed in the SMC (DO-214AB) surface-mount plastic package (Case 403), featuring a modified L-bend leadform for enhanced solder joint reliability and thermal transfer. Cathode is marked by a molded notch on the body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Ground reference terminal | Connected directly to system ground plane; serves as return path for surge current. |
| Cathode | Protected line terminal | Connected to the line being protected (e.g., +48 V rail); conducts surge current to ground when clamped. |
Key Features
| Feature | Design Value |
|---|---|
| 1500 W peak pulse power | Supports robust protection against IEC 61000-4-5 4 kV/2 Ω combination wave surges without degradation. |
| UL 497B certification | Validated for use in safety-critical isolated loop applications including telecom line cards and process controllers. |
| ESD rating >16 kV HBM | Provides secondary ESD immunity for handling and board-level assembly without additional discrete protection. |
| Low zener impedance | Minimizes voltage overshoot during fast transients, improving margin for 3.3 V or 5 V logic interfaces. |
| Pb-free Surmetic package | RoHS-compliant thermoset molding compound with void-free construction ensures long-term reliability under thermal cycling. |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module |
|---|---|
Use Scenario: 48 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: Primary overvoltage clamp placed upstream of DC-DC converter input to prevent regulator latch-up or MOSFET failure. Use Value: Clamps 10/1000 µs surges to ≤64.5 V, maintaining input voltage below 70 V absolute max rating of buck controller ICs. | Use Scenario: LIN bus transceiver power rail in door module subjected to battery reverse connection and jump-start transients. IC Role / Device Role / Timing Role: Unidirectional TVS connected between VCC and GND to absorb reverse-polarity energy and clamp positive spikes. Use Value: Withstands 200 A forward surge current and maintains <5 µA leakage at 13.5 V, preserving low-power sleep mode integrity. |
| Medical Equipment Input Stage | Telecom Isolated Data Line |
Use Scenario: AC/DC adapter output feeding patient-connected monitoring equipment requiring reinforced insulation and low leakage. IC Role / Device Role / Timing Role: Secondary-side TVS on regulated 5 V or 12 V rail to suppress coupling from internal switching noise or external EFT bursts. Use Value: UL 497B recognition confirms suitability for medical isolated loop protection; <5 µA leakage avoids interference with microamp-level sensor bias currents. | Use Scenario: RS-485 transceiver VCC rail in building automation node connected to long outdoor cabling. IC Role / Device Role / Timing Role: Unidirectional clamp protecting transceiver supply against induced lightning surges on shared power/data pairs. Use Value: 64.5 V clamping voltage provides 15 V margin above 48 V nominal loop supply, preventing transceiver shutdown during Category A/B surges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ40A | 600 W peak power, SMB package (smaller footprint, higher RJA = 195 °C/W) | Limited to lower-energy transients; unsuitable for IEC 61000-4-5 Level 4 testing. | Select when board space is constrained and surge threat level is limited to IEC 61000-4-4 EFT only. |
| 1.5SMC40A | Same 1500 W rating and SMC package, but non-Pb-free and obsolete per ON Semi lifecycle notice. | No UL 497B recognition; lacks documented flammability and endurance test validation. | Use only for legacy repair; new designs should specify 1SMC40AT3 for certified reliability and RoHS compliance. |
Compared with SMBJ40A and 1.5SMC40A, the 1SMC40AT3 offers superior surge robustness due to its full 1500 W rating and UL 497B certification, while maintaining compatibility with standard SMC reflow profiles and providing verified low-leakage performance across temperature.
Availability
1SMC40AT3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive ECUs, medical device front-ends, and telecom infrastructure requiring stable component supply and certified surge protection.
Supply support for 1SMC40AT3 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, sensors, and discrete devices for automotive, industrial, and communications markets.
The 1SMC40AT3 belongs to the SMC-series Zener TVS family, engineered for high-energy transient suppression in harsh environments where reliability, certification, and repeatable clamping performance are critical.
FAQ
What is the maximum clamping voltage of the 1SMC40AT3 under rated surge conditions?
The 1SMC40AT3 clamps to a maximum of 64.5 V when subjected to its rated peak pulse current of 32.2 A (10/1000 µs waveform). This value is measured per ON Semiconductor's test conditions and defines the upper voltage limit imposed on protected circuitry during a full-rated transient event. The 1SMC40AT3 achieves this clamping performance while maintaining low dynamic impedance and sub-1 ns response time.
Is the 1SMC40AT3 suitable for bidirectional signal line protection?
No, the 1SMC40AT3 is a unidirectional TVS diode and is not suitable for bidirectional signal line protection such as USB or RS-232. It conducts only in reverse breakdown and blocks forward current beyond ~3.5 V. For bidirectional applications, a dedicated bidirectional TVS like SMAJ40A or a dual-diode array must be used. The 1SMC40AT3 is intended for DC power rail protection where polarity is fixed and known.
Does the 1SMC40AT3 have UL recognition, and what does it cover?
Yes, the 1SMC40AT3 carries UL 497B recognition under file #E210057, category QVGQ2. This certification validates its use in isolated loop circuit protection, covering tests including strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge performance. It confirms suitability for telecom, industrial control, and medical isolated interfaces-unlike basic flammability-only certifications held by some competitors.
What is the thermal resistance and power derating behavior of the 1SMC40AT3?
The 1SMC40AT3 has a junction-to-ambient thermal resistance (RJA) of 165 °C/W on standard FR-4 board and junction-to-lead (RJL) of 54.6 °C/W on 1 in² copper. Its DC power dissipation derates linearly above 25°C ambient (0.75 W at 25°C → 0 W at ~140°C) and above 75°C lead temperature (4.0 W at 75°C → 0 W at ~160°C), per ON Semiconductor's published curves.
How does the 1SMC40AT3 compare to the older 1.5SMC40A part?
The 1SMC40AT3 replaces the 1.5SMC40A with identical electrical specs and SMC package but adds Pb-free construction, UL 497B certification, and updated manufacturing controls. Unlike the 1.5SMC40A, the 1SMC40AT3 is actively supported, documented in current ON Semi datasheets, and qualified for modern reflow profiles. New designs should specify 1SMC40AT3 to ensure supply continuity and compliance.
1SMC40AT3 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:
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- Qualification:
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- Mounting Type:
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- Supplier Device Package:
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1SMC40AT3 FAQ
1.How can I place an order for 1SMC40AT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMC40AT3 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 1SMC40AT3 reliable?
The price and inventory of 1SMC40AT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMC40AT3 is usually 5 days.
3.What payment methods are accepted for 1SMC40AT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMC40AT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMC40AT3?
1SMC40AT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMC40AT3 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 1SMC40AT3?
For technical support, including 1SMC40AT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMC40AT3 requirements.
6.How does Aetrix verify that 1SMC40AT3 is sourced from the original manufacturer or authorized distributors?
All 1SMC40AT3 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 1SMC40AT3 meets industry standards.
7.What is the process for return or replacement of 1SMC40AT3?
All 1SMC40AT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMC40AT3, 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 1SMC40AT3 part is unused and in its original packaging.
Return procedure for 1SMC40AT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMC40AT3 Tags
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