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Vishay General Semiconductor - Diodes Division SM8S20-E3/2D
- Part No.:
- SM8S20-E3/2D
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
SM8S20-E3/2D.pdf
- Description:
- TVS DIODE 20VWM 35.8VC DO218AB
- Quantity:
- Payment:
- Shipping:
Inventory:5,288
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Product details
Overview
SM8S20-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 systems. It features a 20 V stand-off voltage (VWM), 35.8 V maximum clamping voltage at 184 A peak pulse current (10/1000 μs), 6600 W peak pulse power, and AEC-Q101 qualification for under-hood applications.
For engineers reviewing the SM8S20-E3/2D datasheet, SM8S20-E3/2D pinout, SM8S20-E3/2D application, or SM8S20-E3/2D equivalent, key selection criteria include clamping performance under ISO 7637-2 load dump waveforms, thermal resistance (0.90 °C/W), DO-218AB package mounting compatibility, and TJ = 175 °C operation for engine control units and body electronics.
Technical Context
The SM8S20-E3/2D employs passivated anisotropic rectifier technology to achieve low leakage (<10 μA at VWM) and low forward voltage drop (≤1.8 V at 100 A). Its junction design supports continuous operation from –55 °C to +175 °C with MSL Level 1 moisture sensitivity and 245 °C reflow capability.
It delivers 6600 W surge handling per 10/1000 μs waveform and 5200 W per 10/10 000 μs waveform, meeting ISO 7637-2 test conditions for automotive transients. The heatsink terminal serves as the anode, enabling direct thermal coupling to PCB copper planes for efficient heat dissipation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20 V - Maximum reverse working voltage before clamping begins; defines safe operating range in 12 V automotive circuits. |
| VC @ IPPM | 35.8 V - Clamped voltage at 184 A peak pulse; ensures downstream ICs see <36 V during load dump events. |
| PPPM (10/1000 μs) | 6600 W - Peak surge power handling; sustains high-energy transients without failure in alternator load dump scenarios. |
| RθJC | 0.90 °C/W - Junction-to-case thermal resistance; enables effective heat transfer to heatsink or PCB copper when mounted per DO-218AB layout. |
| TJ max. | +175 °C - Maximum junction temperature; supports placement near hot engine compartments without derating. |
| AEC-Q101 | Qualified - Certified for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per stress test plan. |
Pinout & Package
Package: DO-218AB - Surface-mount molded case with metal heatsink terminal (anode), matte tin-plated leads, UL 94 V-0 rated compound, and JESD 201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Lead 1 | Cathode | Signal-side connection; connects to protected line (e.g., battery rail); carries full surge current during clamping. |
| Lead 2 / Metal Heatsink | Anode | Thermal and electrical ground reference; must be soldered to large copper area for thermal management and low-inductance return path. |
Key Features
| Feature | Design Value |
|---|---|
| Unidirectional polarity | Enables precise clamping only on positive transients-ideal for 12 V DC supply rails where reverse voltage is not expected. |
| Low leakage current | <10 μA at 20 V VWM and 25 °C; minimizes standby power loss in always-on vehicle modules like telematics and gateway ECUs. |
| High surge capability | 184 A peak pulse current (10/1000 μs); withstands repeated load dump events per ISO 7637-2 Pulse 5a without degradation. |
| DO-218AB thermal design | 0.90 °C/W RθJC with heatsink terminal; allows >8 W steady-state dissipation when mounted on ≥25 cm² 2 oz copper. |
Applications
| Engine Control Unit (ECU) Power Protection | Automotive Body Control Module (BCM) |
|---|---|
|
Use Scenario: Protects microcontroller power inputs from alternator load dump transients during battery disconnect/reconnect events. IC Role / Device Role / Timing Role: Primary overvoltage clamp on main 12 V input rail upstream of DC/DC converters and LDOs. Use Value: Limits voltage to ≤35.8 V during 6600 W surges, preventing latch-up or permanent damage to 3.3 V/5 V logic supplies. |
Use Scenario: Shields LIN bus transceivers and window motor drivers from switching noise and inductive kickback in door modules. IC Role / Device Role / Timing Role: Localized TVS at point-of-load for sub-system power distribution networks. Use Value: Provides <10 μA leakage at 20 V to preserve sleep-mode current budgets while clamping fast 10/1000 μs spikes. |
| Advanced Driver Assistance Systems (ADAS) Camera Power | Electric Power Steering (EPS) Control Board |
|
Use Scenario: Safeguards image sensor and SerDes power rails against ignition-induced transients in front-facing camera modules. IC Role / Device Role / Timing Role: High-reliability transient suppressor placed directly at connector entry point. Use Value: AEC-Q101 qualification and 175 °C operation ensure stable clamping performance in sealed, thermally constrained enclosures. |
Use Scenario: Guards MCU and gate driver ICs from motor commutation surges and battery reversal transients in EPS actuator boards. IC Role / Device Role / Timing Role: Bidirectional-capable protection element used in unidirectional configuration for 12 V supply rail. Use Value: 5200 W rating at 10/10 000 μs waveform matches long-duration load dump profiles defined in ISO 7637-2. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ20A-E3/5AT | Lower PPPM (400 W vs. 6600 W); SMA package; 32.4 V clamping at 12.3 A. | Suitable for low-energy ESD/surge; not rated for ISO 7637-2 load dump. | Select SMAJ20A-E3/5AT only for board-level ESD protection where energy is <100 mJ. |
| TPSMD20H | Same DO-218AB package; 34.4 V clamping at 145 A; 6000 W PPPM; no AEC-Q101 documentation confirmed. | Validated for industrial 12 V systems; lacks automotive qualification evidence in public datasheet. | Choose TPSMD20H if AEC-Q101 is not required and thermal performance (RθJC = 0.95 °C/W) is acceptable. |
Compared with SMAJ20A-E3/5AT and TPSMD20H, the SM8S20-E3/2D uniquely combines 6600 W surge capacity, AEC-Q101 qualification, and 0.90 °C/W thermal resistance in DO-218AB-making it the only option qualified for under-hood automotive load dump protection per ISO 7637-2.
Availability
SM8S20-E3/2D is available at Aetrix Electronics and suitable for automotive engine control units, body control modules, ADAS camera power systems, and electric power steering designs requiring stable component supply across extended temperature and high-surge environments.
Supply support for SM8S20-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 diodes, rectifiers, MOSFETs, and protection devices with emphasis on automotive, industrial, and computing applications.
The SM8S series is part of Vishay's PAR® TVS platform, engineered specifically for high-energy automotive load dump protection with focus on thermal robustness, AEC-Q101 compliance, and DO-218AB mechanical reliability.
FAQ
What is the clamping voltage of the SM8S20-E3/2D at its rated peak pulse current?
The SM8S20-E3/2D has a maximum clamping voltage (VC) of 35.8 V at its specified peak pulse current (IPPM) of 184 A under a 10/1000 μs waveform. This value is measured per the conditions in Vishay document 88387 and ensures protected circuitry remains below critical overvoltage thresholds during automotive load dump events. The SM8S20-E3/2D maintains this clamping performance across its full operating temperature range.
Is the SM8S20-E3/2D suitable for bidirectional transient protection?
No, the SM8S20-E3/2D is unidirectional only, with the heatsink terminal designated as the anode and Lead 1 as the cathode. It clamps only positive-going transients on the cathode side. For bidirectional protection, a separate device such as the SM8S20A-E3/2D (which offers symmetrical breakdown) would be required. The SM8S20-E3/2D datasheet explicitly states "Available in uni-directional polarity only."
Does the SM8S20-E3/2D meet ISO 7637-2 requirements?
Yes, the SM8S20-E3/2D meets ISO 7637-2 surge specifications under defined test conditions, as stated in the Vishay document 88387. Its 6600 W (10/1000 μs) and 5200 W (10/10 000 μs) ratings align with Pulse 5a load dump waveforms. Compliance is verified through characterization-not certified as a standalone standard-but the device is widely deployed in automotive modules validated to ISO 7637-2.
What is the thermal resistance from junction to case for the SM8S20-E3/2D?
The SM8S20-E3/2D has a typical thermal resistance (RθJC) of 0.90 °C/W from junction to case, measured under standard test conditions. This low value is enabled by the DO-218AB package's metal heatsink terminal, which must be soldered to a substantial copper area to realize full thermal performance. The SM8S20-E3/2D's RθJC supports continuous 8 W dissipation at TC = 25 °C.
How is the polarity configured on the SM8S20-E3/2D DO-218AB package?
On the SM8S20-E3/2D in DO-218AB packaging, the metal heatsink terminal (Lead 2) is the anode, and Lead 1 is the cathode. The Vishay datasheet explicitly notes "Polarity: Heatsink is anode," meaning the heatsink must be connected to the system ground or lower-potential node, while the cathode connects to the line being protected. This configuration is essential for correct unidirectional clamping behavior in the SM8S20-E3/2D.
SM8S20-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):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 35.8V
- Current - Peak Pulse (10/1000µs):
- 184A
- 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
SM8S20-E3/2D FAQ
1.How can I place an order for SM8S20-E3/2D through Aetrix?
Please submit a Request for Quotation (RFQ) for SM8S20-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 SM8S20-E3/2D reliable?
The price and inventory of SM8S20-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 SM8S20-E3/2D is usually 5 days.
3.What payment methods are accepted for SM8S20-E3/2D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM8S20-E3/2D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM8S20-E3/2D?
SM8S20-E3/2D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM8S20-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 SM8S20-E3/2D?
For technical support, including SM8S20-E3/2D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM8S20-E3/2D requirements.
6.How does Aetrix verify that SM8S20-E3/2D is sourced from the original manufacturer or authorized distributors?
All SM8S20-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 SM8S20-E3/2D meets industry standards.
7.What is the process for return or replacement of SM8S20-E3/2D?
All SM8S20-E3/2D units undergo pre-shipment inspection (PSI). If there is an issue with SM8S20-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 SM8S20-E3/2D part is unused and in its original packaging.
Return procedure for SM8S20-E3/2D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM8S20-E3/2D Tags
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