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Vishay General Semiconductor - Diodes Division SM8S40A-E3/2D
- Part No.:
- SM8S40A-E3/2D
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
SM8S40A-E3/2D.pdf
- Description:
- TVS DIODE 40VWM 64.5VC DO218AB
- Quantity:
- Payment:
- Shipping:
Inventory:9,928
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Product details
Overview
SM8S40A-E3/2D from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor (TVS) designed for automotive load dump protection in high-reliability 12 V/24 V systems. It features a 40 V stand-off voltage (VWM), 64.5 V maximum clamping voltage (VC) at 102 A peak pulse current (IPPM), and 6600 W peak pulse power (10/1000 μs), operating up to TJ = 175 °C in the DO-218AB package.
For engineers reviewing the SM8S40A-E3/2D datasheet, SM8S40A-E3/2D pinout, SM8S40A-E3/2D application, or SM8S40A-E3/2D equivalent, key selection criteria include clamping performance under ISO 7637-2 load dump waveforms, AEC-Q101 qualification, thermal resistance (RθJC = 0.90 °C/W), and unidirectional polarity with heatsink-anode configuration.
Technical Context
This TVS diode employs passivated anisotropic rectifier technology optimized for junction stability at TJ = 175 °C, enabling sustained operation in under-hood automotive environments. Its unidirectional structure provides low forward voltage drop (VF ≤ 1.8 V at 100 A) and low reverse leakage (ID ≤ 10 μA at VWM = 40 V, TA = 25 °C).
The device meets MSL Level 1 per J-STD-020 (peak reflow = 245 °C), complies with RoHS Directive 2011/65/EU, and is qualified to AEC-Q101. Its DO-218AB case delivers high surge capability (IFSM = 700 A) and thermal performance via direct metal heatsink contact.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - Maximum continuous reverse operating voltage before clamping begins; defines system working voltage margin. |
| VC @ IPPM | 64.5 V - Clamped voltage at 102 A (10/1000 μs); ensures downstream ICs remain below absolute max ratings during transients. |
| PPPM (10/1000 μs) | 6600 W - Peak surge power handling; supports ISO 7637-2 Load Dump Test Pulse 5a (12 V systems) without failure. |
| TJ max. | 175 °C - Maximum junction temperature; enables placement near hot engine components without derating penalties. |
| RθJC | 0.90 °C/W - Junction-to-case thermal resistance; allows precise thermal design when mounted on copper heatsink area. |
| AEC-Q101 | Qualified - Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per stress test plan. |
Pinout & Package
Package: DO-218AB - Surface-mount, single-ended anode-heatsink configuration with matte tin-plated leads; UL 94 V-0 molding compound; anode terminal integrated into metal heatsink base (Lead 2).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Lead 1 | Cathode | Connected to protected line (e.g., battery rail); carries full transient current during clamping. |
| Lead 2 / Metal Heatsink | Anode | Must be soldered to large copper pour or heatsink; serves as primary thermal path and electrical return. |
Key Features
| Feature | Design Value |
|---|---|
| Junction passivation | Optimized anisotropic rectifier process ensures stable VBR over lifetime and temperature, critical for long-term automotive deployment. |
| Unidirectional polarity | Enables low VF (≤1.8 V) conduction during forward surges while providing precise reverse clamping-ideal for DC supply rails. |
| MSL Level 1 rating | Supports standard SMT reflow profiles up to 245 °C peak without moisture-induced damage or delamination. |
| Low ID at VWM | ≤10 μA leakage at 40 V and 25 °C minimizes standby power loss in always-on vehicle modules (e.g., body control units). |
Applications
| Automotive Body Control Module (BCM) | Engine Control Unit (ECU) Power Input |
|---|---|
Use Scenario: Protects microcontroller power rails from alternator load dump transients during battery disconnection events in 12 V systems. IC Role / Device Role / Timing Role: Unidirectional TVS clamps voltage spikes within 1 ns to limit rail excursion to ≤64.5 V. Use Value: Prevents latch-up or permanent damage to 5 V/3.3 V LDOs and MCU I/Os exposed to ISO 7637-2 Pulse 5a. |
Use Scenario: Shields high-side driver ICs and sensor interfaces from inductive switching noise generated by fuel injectors or solenoids. IC Role / Device Role / Timing Role: Absorbs repetitive 50–100 A surges (8.3 ms half-sine) without degradation due to 700 A IFSM rating. Use Value: Maintains signal integrity and prevents reset faults during cold-cranking and cranking transients. |
| ADAS Camera Power Supply | Electric Power Steering (EPS) ECU |
Use Scenario: Guards image sensor and SerDes interface power against coupled transients from nearby motor drivers in compact camera housings. IC Role / Device Role / Timing Role: Provides low-capacitance (<45 pF at 0 V) clamping without distorting high-speed video signals. Use Value: Enables reliable operation at TJ = 175 °C in sealed enclosures with no active cooling required. |
Use Scenario: Safeguards motor gate drivers and position sensors from regenerative energy spikes during rapid deceleration. IC Role / Device Role / Timing Role: Delivers 5200 W surge handling (10/10,000 μs) to meet extended-duration load dump requirements. Use Value: Eliminates need for secondary TVS stages, reducing BOM count and PCB area in space-constrained EPS modules. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40A-E3/5BT | Lower PPPM (400 W vs. 6600 W); SMA package (RθJC ≈ 45 °C/W vs. 0.90 °C/W); VWM = 40 V, VC = 64.5 V. | Not suitable for load dump; limited to ESD/low-energy transients in consumer electronics. | Select only for non-automotive, low-power signal-line protection where surge energy is <100 mJ. |
| TPSMD40A | Same DO-218AB package; lower clamping (VC = 62.5 V at 105 A); AEC-Q101 qualified; PPPM = 6600 W. | Compatible for load dump but requires validation of thermal interface due to different RθJC (1.0 °C/W). | Valid alternative if tighter clamping margin is needed and layout allows verification of heatsink attachment robustness. |
Compared with SMAJ40A-E3/5BT, SM8S40A-E3/2D delivers 16.5× higher surge power and superior thermal management for automotive power rails; versus TPSMD40A, it offers identical surge rating but slightly higher clamping voltage, simplifying margin analysis in existing designs.
Availability
SM8S40A-E3/2D is available at Aetrix Electronics and suitable for automotive body control modules, engine control units, and ADAS camera power supplies requiring stable component supply across extended temperature and lifecycle demands.
Supply support for SM8S40A-E3/2D 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 high-reliability diodes, MOSFETs, and optoelectronics for automotive, industrial, and computing markets.
The SM8SxxA series was developed specifically for AEC-Q101-compliant automotive load dump protection, emphasizing high-temperature stability (TJ = 175 °C), low-leakage unidirectional clamping, and robust surge endurance in DO-218AB packaging.
FAQ
What is the clamping voltage of SM8S40A-E3/2D at its rated peak pulse current?
The SM8S40A-E3/2D has a maximum clamping voltage (VC) of 64.5 V at its specified peak pulse current (IPPM) of 102 A under a 10/1000 μs waveform. This value is measured per the conditions defined in the Vishay datasheet (Document Number: 88387), ensuring predictable overvoltage limiting for downstream circuitry during ISO 7637-2 load dump events. The SM8S40A-E3/2D maintains this clamping performance across its full operating temperature range.
Is SM8S40A-E3/2D suitable for bidirectional transient suppression?
No, SM8S40A-E3/2D is a unidirectional TVS diode and is not rated for bidirectional operation. Its electrical characteristics-including breakdown voltage (VBR min = 44.4 V), stand-off voltage (VWM = 40 V), and anode-heatsink polarity-are defined only for reverse-biased clamping. For bidirectional protection, a dedicated bidirectional part such as SM8S40CA-E3/2D must be used. The SM8S40A-E3/2D datasheet explicitly states "Available in uni-directional polarity only".
What does the "E3/2D" suffix indicate in SM8S40A-E3/2D?
The "E3" suffix denotes RoHS-compliant, matte tin-plated leads qualified to JESD 201 Class 2 whisker resistance, while "2D" specifies the preferred packaging: 13-inch plastic tape and reel with 750 units per reel and anode orientation toward the sprocket hole. This packaging format ensures compatibility with automated SMT placement equipment and supports traceable, controlled assembly processes. The full designation SM8S40A-E3/2D uniquely identifies this qualified variant of the SM8S40A-E3/2D.
How does SM8S40A-E3/2D meet automotive reliability requirements?
SM8S40A-E3/2D is AEC-Q101 qualified, having passed stress tests including high-temperature reverse bias (HTRB), temperature cycling, and mechanical shock. Its DO-218AB package achieves MSL Level 1 per J-STD-020 (245 °C peak reflow), and its junction operates reliably up to 175 °C. These qualifications validate the SM8S40A-E3/2D for use in under-hood automotive applications where thermal and mechanical robustness are mandatory.
Can SM8S40A-E3/2D be used without a heatsink?
No-SM8S40A-E3/2D requires mounting its metal heatsink (Lead 2/anode) to a substantial copper area or external heatsink to achieve rated power dissipation. With RθJC = 0.90 °C/W, thermal performance degrades rapidly without proper heat spreading; operation at full 6600 W surge without thermal management risks junction overheating and parametric shift. The SM8S40A-E3/2D datasheet mandates heatsink connection for compliance with maximum ratings.
SM8S40A-E3/2D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-218AB
- 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):
- 102A
- Power - Peak Pulse:
- 6600W (6.6kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-218AB
SM8S40A-E3/2D FAQ
1.How can I place an order for SM8S40A-E3/2D through Aetrix?
Please submit a Request for Quotation (RFQ) for SM8S40A-E3/2D 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 SM8S40A-E3/2D reliable?
The price and inventory of SM8S40A-E3/2D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM8S40A-E3/2D is usually 5 days.
3.What payment methods are accepted for SM8S40A-E3/2D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM8S40A-E3/2D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM8S40A-E3/2D?
SM8S40A-E3/2D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM8S40A-E3/2D 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 SM8S40A-E3/2D?
For technical support, including SM8S40A-E3/2D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM8S40A-E3/2D requirements.
6.How does Aetrix verify that SM8S40A-E3/2D is sourced from the original manufacturer or authorized distributors?
All SM8S40A-E3/2D 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 SM8S40A-E3/2D meets industry standards.
7.What is the process for return or replacement of SM8S40A-E3/2D?
All SM8S40A-E3/2D units undergo pre-shipment inspection (PSI). If there is an issue with SM8S40A-E3/2D, 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 SM8S40A-E3/2D part is unused and in its original packaging.
Return procedure for SM8S40A-E3/2D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM8S40A-E3/2D Tags
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