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Vishay General Semiconductor - Diodes Division SM5S40ATHE3/I
- Part No.:
- SM5S40ATHE3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AC
- Datasheet:
-
SM5S40ATHE3/I.pdf
- Description:
- TVS DIODE 40VWM 64.5VC DO218AC
- Quantity:
- Payment:
- Shipping:
Inventory:8,921
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Product details
Overview
SM5S40ATHE3/I from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor in DO-218AC package, rated for 40 V stand-off voltage (VWM), 46.8 V nominal breakdown (VBR), 64.5 V clamping voltage at 150 A peak pulse current, and 3600 W peak pulse power (10/1000 μs). It operates from −55 °C to +175 °C and is AEC-Q101 qualified for automotive load dump protection.
For engineers reviewing the SM5S40ATHE3/I datasheet, SM5S40ATHE3/I pinout, SM5S40ATHE3/I application, or SM5S40ATHE3/I equivalent, this device serves as a high-reliability, high-surge-capability TVS diode optimized for automotive 12 V/24 V systems requiring ISO7637-2 compliance, low leakage (<10 μA at VWM), and robust thermal stability up to TJ = 175 °C.
Technical Context
The SM5S40ATHE3/I uses passivated anisotropic rectifier technology with junction passivation optimized for stable breakdown behavior across temperature. Its unidirectional polarity configures the metal heatsink as the anode, enabling direct thermal coupling to PCB copper for enhanced power dissipation.
It delivers 3600 W surge capability under 10/1000 μs waveform and maintains 2800 W under longer 10/10 000 μs pulses-critical for automotive load dump transients. With RθJC = 1.0 °C/W and PD = 5 W on infinite heatsink, it supports high-power transient suppression without external heat sinking in properly designed layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - Maximum continuous reverse operating voltage before conduction begins; defines system working voltage margin. |
| VBR (nom) | 46.8 V - Breakdown voltage at 5 mA test current; ensures reliable triggering above normal operating rail. |
| VC @ IPPM | 64.5 V - Clamping voltage at 150 A peak pulse; limits downstream IC stress during load dump events. |
| PPPM (10/1000 μs) | 3600 W - Peak surge power handling; meets ISO7637-2 Pulse 5a requirements for 12 V automotive systems. |
| TJ max | +175 °C - Maximum junction temperature; enables operation in under-hood environments without derating. |
| Leakage @ VWM | <10 μA - Low reverse leakage preserves battery life and avoids false triggering in always-on circuits. |
| Package | DO-218AC - Thermally enhanced surface-mount package with metal heatsink terminal; supports >5 W steady-state dissipation. |
Pinout & Package
Package: DO-218AC - thermally optimized surface-mount case with exposed metal heatsink (anode) and molded plastic body meeting UL 94 V-0. Leads are matte tin plated, solderable per J-STD-002 and JESD 22-B102, and qualified to JESD 201 Class 2 whisker test.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Metal Heatsink) | Positive terminal / thermal path | Connected to system ground or chassis; provides primary thermal conduction path to PCB copper pour. |
| Cathode (Lead 1) | Transient voltage sensing and clamping node | Connected to protected line (e.g., battery rail); conducts surge current to anode when V > VBR. |
Key Features
| Feature | Design Value |
|---|---|
| Junction passivation optimized design | Stable VBR drift ≤0.092 %/°C enables predictable clamping across −55 °C to +175 °C operating range. |
| AEC-Q101 qualification (HE3 suffix) | Validated reliability for automotive under-hood applications including temperature cycling, humidity bias, and mechanical shock. |
| MSL Level 1 (245 °C peak reflow) | Compatible with standard lead-free SMT reflow profiles without moisture sensitivity concerns or baking requirements. |
| ISO7637-2 compliant (Pulse 5a) | Withstands 3600 W load dump surges typical of alternator disconnection events in 12 V vehicle electrical systems. |
Applications
| Automotive Load Dump Protection | Industrial Power Supply Input Protection |
|---|---|
Use Scenario: Protecting ECUs, infotainment modules, and ADAS sensors from alternator-induced load dump transients in 12 V vehicle systems. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between battery rail and ground, clamping transients within 10 ns to limit voltage to ≤64.5 V. Use Value: Prevents damage to downstream DC-DC converters and microcontrollers by absorbing up to 3600 W of transient energy without degradation. | Use Scenario: Safeguarding programmable logic controllers (PLCs) and motor drives against switching surges from inductive loads in factory automation. IC Role / Device Role / Timing Role: Primary overvoltage clamp on 24 V DC input bus, triggered only during fault conditions exceeding 40 V. Use Value: Maintains <10 μA leakage at 40 V to avoid unnecessary power loss while delivering 150 A peak surge current capability. |
| Telecom Power Interface Protection | Commercial Vehicle Battery Management |
Use Scenario: Shielding base station power supplies from lightning-induced surges coupled through long DC feeder lines. IC Role / Device Role / Timing Role: High-energy TVS placed at DC input connector, coordinated with upstream fuses and downstream filters. Use Value: Achieves 2800 W rating under 10/10 000 μs waveform-matching extended surge durations seen in telecom infrastructure. | Use Scenario: Securing BMS monitoring circuits in heavy-duty trucks where battery voltage can spike to 45 V during regenerative braking. IC Role / Device Role / Timing Role: Standoff-rated protector on analog sensor inputs (e.g., voltage dividers), blocking conduction below 40 V. Use Value: Ensures signal integrity with 0.092 %/°C VBR tempco, minimizing calibration drift across wide ambient temperature swings. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SM5S40AHM3 | Same VWM/VBR/VC ratings and DO-218AC package; HM3 suffix indicates halogen-free, RoHS-compliant construction with no change in electrical specs. | No functional difference; HM3 replaces HE3 for new designs due to updated environmental compliance requirements. | Select SM5S40AHM3 for new designs requiring halogen-free materials and latest Vishay manufacturing standards. |
| SMAJ40A | Lower PPPM (400 W vs. 3600 W), SMA package (RθJC ≈ 40 °C/W), and lower IFSM (40 A vs. 500 A); not AEC-Q101 qualified. | Suitable only for low-energy transients (e.g., ESD, relay bounce); insufficient for automotive load dump or industrial inductive switching. | Use SMAJ40A only in cost-sensitive, non-automotive applications with <500 W surge requirements and no AEC-Q101 mandate. |
Compared with SM5S40ATHE3/I, SM5S40AHM3 offers identical electrical and thermal performance with updated material compliance, while SMAJ40A provides basic clamping at significantly reduced surge capacity and thermal robustness-making it unsuitable as a drop-in replacement in high-reliability systems.
Availability
SM5S40ATHE3/I is available at Aetrix Electronics and suitable for automotive electronics, industrial power interfaces, and telecom infrastructure requiring stable component supply, AEC-Q101 qualification, and high-temperature operational reliability.
Supply support for SM5S40ATHE3/I 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
Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, MOSFETs, optoelectronics, and passive components with emphasis on reliability, power handling, and automotive-grade qualification.
The SM5SxxAT family was engineered specifically for high-energy transient suppression in harsh automotive and industrial environments, prioritizing thermal stability, surge endurance, and AEC-Q101 compliance over general-purpose TVS trade-offs.
FAQ
What is the maximum clamping voltage of the SM5S40ATHE3/I at its rated peak pulse current?
The SM5S40ATHE3/I has a maximum clamping voltage (VC) of 64.5 V at 150 A peak pulse current (IPPM) under 10/1000 μs waveform. This value is measured per the standard test condition defined in the Vishay datasheet (Document Number: 87609), and ensures downstream circuitry remains within safe operating voltage limits during automotive load dump events. The SM5S40ATHE3/I maintains this clamping performance across its full operating temperature range.
Is the SM5S40ATHE3/I suitable for new automotive designs?
No-the SM5S40ATHE3/I is marked "Not For New Designs" in the official Vishay documentation, with SM5S40AHM3 designated as the recommended alternative. While SM5S40ATHE3/I remains available for legacy support and existing production, new designs should use SM5S40AHM3, which retains identical electrical and thermal specifications but meets updated halogen-free and environmental compliance requirements. The SM5S40ATHE3/I is still fully functional and qualified to AEC-Q101.
How does the DO-218AC package of the SM5S40ATHE3/I improve thermal performance compared to SMA or SMB packages?
Unlike standard SMA or SMB packages, the DO-218AC package of the SM5S40ATHE3/I features an integrated metal heatsink terminal acting as the anode, achieving a typical junction-to-case thermal resistance (RθJC) of just 1.0 °C/W. This allows the SM5S40ATHE3/I to dissipate 5 W continuously on an infinite heatsink-over 10× more than SMAJ-class devices-and sustain 3600 W transient surges without thermal runaway. The exposed metal pad enables direct thermal coupling to large PCB copper areas.
Does the SM5S40ATHE3/I meet ISO7637-2 requirements for automotive applications?
Yes-the SM5S40ATHE3/I is explicitly stated in the Vishay datasheet to meet ISO7637-2 surge specifications, particularly Pulse 5a (load dump), under defined test conditions. Its 3600 W peak pulse power rating (10/1000 μs) and 2800 W rating (10/10 000 μs) align with the energy levels required for 12 V automotive systems. The SM5S40ATHE3/I is also AEC-Q101 qualified, confirming its suitability for automotive under-hood deployment.
What is the polarity configuration and terminal identification for the SM5S40ATHE3/I?
SM5S40ATHE3/I is unidirectional, with the metal heatsink serving as the anode and Lead 1 (smaller lead) as the cathode. Polarity is marked on the device body with a band indicating the cathode end. In PCB layout, the anode must be connected to system ground or chassis, and the cathode to the protected line (e.g., battery rail). Reversing polarity will prevent proper clamping and may cause device failure. This configuration is confirmed in the "Mechanical Data" section of the SM5S40ATHE3/I datasheet.
SM5S40ATHE3/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-218AC
- Series:
- PAR®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 56A
- Power - Peak Pulse:
- 3600W (3.6kW)
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-218AC
SM5S40ATHE3/I FAQ
1.How can I place an order for SM5S40ATHE3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SM5S40ATHE3/I 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 SM5S40ATHE3/I reliable?
The price and inventory of SM5S40ATHE3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM5S40ATHE3/I is usually 5 days.
3.What payment methods are accepted for SM5S40ATHE3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM5S40ATHE3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM5S40ATHE3/I?
SM5S40ATHE3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM5S40ATHE3/I 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 SM5S40ATHE3/I?
For technical support, including SM5S40ATHE3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM5S40ATHE3/I requirements.
6.How does Aetrix verify that SM5S40ATHE3/I is sourced from the original manufacturer or authorized distributors?
All SM5S40ATHE3/I 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 SM5S40ATHE3/I meets industry standards.
7.What is the process for return or replacement of SM5S40ATHE3/I?
All SM5S40ATHE3/I units undergo pre-shipment inspection (PSI). If there is an issue with SM5S40ATHE3/I, 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 SM5S40ATHE3/I part is unused and in its original packaging.
Return procedure for SM5S40ATHE3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM5S40ATHE3/I Tags
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