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Vishay General Semiconductor - Diodes Division SM8S20ATHE3/I
- Part No.:
- SM8S20ATHE3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AC
- Datasheet:
-
SM8S20ATHE3/I.pdf
- Description:
- TVS DIODE 20VWM 32.4VC DO218AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,508
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Product details
Overview
SM8S20ATHE3/I 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 22.2–24.5 V breakdown voltage (VBR), 6600 W peak pulse power (10/1000 μs), 32.4 V clamping voltage at 204 A, 175 °C junction rating, and DO-218AC package with heatsink-anode polarity.
For engineers reviewing the SM8S20ATHE3/I datasheet, SM8S20ATHE3/I pinout, SM8S20ATHE3/I application, or SM8S20ATHE3/I equivalent, this device serves as a high-surge-capability, AEC-Q101-qualified TVS optimized for under-hood automotive electronics where thermal stability, low leakage (<10 μA at VWM), and ISO7637-2 compliance are critical selection criteria.
Technical Context
This TVS diode employs passivated anisotropic rectifier technology to achieve stable 175 °C operation and low forward voltage drop (≤1.8 V at 100 A). Its DO-218AC case provides direct metal heatsink mounting, enabling efficient thermal dissipation with RθJC = 0.90 °C/W.
The device is rated for unidirectional polarity only, with cathode on lead 1 and anode on the metal heatsink (lead 2). It meets MSL Level 1 per J-STD-020 and passes JESD201 Class 2 whisker testing due to its matte tin-plated leads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 22.2 / 23.4 / 24.5 V - ensures reliable triggering above 20 V system stand-off while accommodating manufacturing tolerance and temperature drift |
| VWM | 20.0 V - maximum continuous reverse operating voltage compatible with 12 V automotive battery systems including load dump transients |
| IPPM (10/1000 μs) | 204 A - delivers robust surge immunity against ISO7637-2 Pulse 5a (load dump) without degradation |
| VC @ IPPM | 32.4 V - clamps transient energy to safe levels for downstream 36 V-rated ICs and power stages |
| TJ max | +175 °C - supports under-hood placement near engines or powertrain modules without derating |
| PPPM (10/1000 μs) | 6600 W - enables single-device protection of high-current circuits such as alternator output lines |
| Leakage @ VWM, 25 °C | ≤10 μA - minimizes standby power loss in always-on vehicle networks (e.g., CAN, LIN) |
Pinout & Package
Package: DO-218AC - thermally enhanced surface-mount case with integral metal heatsink (anode terminal); RoHS-compliant, AEC-Q101 qualified, MSL Level 1, LF peak 245 °C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Lead 1 | Cathode | Connected to protected circuit node; reverse-biased during normal operation; conducts during overvoltage events |
| Lead 2 / Metal Heatsink | Anode | Primary thermal path to PCB copper pour or heatsink; must be soldered to large copper area for RθJC = 0.90 °C/W performance |
Key Features
| Feature | Design Value |
|---|---|
| Junction passivation + anisotropic rectifier tech | Enables stable 175 °C operation and <10 μA leakage at VWM, critical for long-life automotive deployments |
| DO-218AC metal heatsink construction | Provides direct thermal conduction path with 0.90 °C/W RθJC, eliminating need for external heatsinks in most 12 V applications |
| AEC-Q101 qualification & HE3 suffix | Confirms reliability for automotive use, including JESD201 Class 2 whisker resistance and MSL Level 1 moisture sensitivity |
| ISO7637-2 Pulse 5a compliance | Validated for 12 V system load dump protection up to 6600 W, meeting OEM-level surge immunity requirements |
Applications
| Engine Control Unit (ECU) Power Input | Automotive Body Control Module (BCM) |
|---|---|
|
Use Scenario: Protects ECU 12 V supply rail from alternator load dump transients during battery disconnect events. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between battery input and DC-DC converter input stage. Use Value: Limits transient voltage to ≤32.4 V, preventing damage to 36 V-rated buck controllers and microcontrollers while sustaining 204 A surge current. |
Use Scenario: Shields BCM power inputs from switching surges generated by high-current loads (e.g., door locks, lighting relays). IC Role / Device Role / Timing Role: Primary overvoltage suppression device on fused 12 V feed, upstream of LDOs and CAN transceivers. Use Value: Maintains <10 μA leakage at 20 V to avoid battery drain in sleep mode, while clamping fast transients within 1 ns response time. |
| ADAS Camera Power Supply | Electric Power Steering (EPS) Motor Driver |
|
Use Scenario: Safeguards image sensor and ISP power rails in front-facing ADAS cameras exposed to engine bay thermal and electrical stress. IC Role / Device Role / Timing Role: Final-stage TVS on 5 V or 3.3 V regulated output, guarding against coupled transients from nearby high-power circuits. Use Value: Operates reliably at 175 °C ambient, ensuring protection integrity during extended highway driving with hood temperatures exceeding 105 °C. |
Use Scenario: Protects gate drivers and current sense amplifiers in EPS motor control units subjected to repetitive inductive switching surges. IC Role / Device Role / Timing Role: High-energy TVS mounted directly on power board near H-bridge, shunting surge current to chassis ground via heatsink. Use Value: Withstands ≥700 A non-repetitive forward surge (IFSM), enabling resilience against fault-induced back-EMF spikes during motor stall conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SM8S20AHM3 | Same VBR, VWM, and PPPM; uses HM3 suffix indicating halogen-free molding compound and slightly different internal construction | Identical automotive qualification (AEC-Q101), but HM3 variant is designated for new designs per Vishay's "Not For New Designs" notice for HE3 series | Select SM8S20AHM3 for new production programs requiring long-term availability and halogen-free compliance; SM8S20ATHE3/I remains valid for legacy design support and existing BOMs. |
| SMAJ20A | Lower PPPM (400 W vs. 6600 W), smaller SMA package (RθJC ≈ 50 °C/W), no AEC-Q101 qualification | Limited to low-energy consumer or industrial applications; unsuitable for automotive load dump or under-hood use | Use SMAJ20A only in cost-sensitive, non-automotive applications with <50 A surge exposure; not a functional replacement for SM8S20ATHE3/I in automotive contexts. |
Compared with SM8S20AHM3, the SM8S20ATHE3/I offers identical electrical protection but lacks halogen-free certification and has end-of-life status per Vishay documentation; versus SMAJ20A, it delivers 16.5× higher surge power and automotive-grade reliability-making it irreplaceable for load dump-critical systems.
Availability
SM8S20ATHE3/I is available at Aetrix Electronics and suitable for automotive ECU protection, body control module hardening, ADAS camera power conditioning, and electric power steering surge suppression requiring stable component supply across extended production lifecycles.
Supply support for SM8S20ATHE3/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 high-reliability diodes, MOSFETs, and passive components for automotive, industrial, and computing markets.
The SM8SxxAT family was engineered specifically for AEC-Q101-compliant automotive transient suppression, emphasizing thermal robustness (175 °C), high surge capability (up to 6600 W), and DO-218AC mechanical stability in harsh under-hood environments.
FAQ
What does the "HE3" suffix mean in SM8S20ATHE3/I?
The HE3 suffix in SM8S20ATHE3/I indicates RoHS-compliant packaging with matte tin-plated leads, AEC-Q101 qualification, and compliance with JESD201 Class 2 whisker testing. It also denotes tape-and-reel packaging (750 units per 13″ reel) with anode orientation toward sprocket holes. This suffix distinguishes it from non-automotive variants and confirms suitability for automotive production environments.
Is SM8S20ATHE3/I suitable for 24 V commercial vehicle applications?
No-SM8S20ATHE3/I is specified for 20 V stand-off (VWM) and 22.2–24.5 V breakdown, making it appropriate for 12 V automotive systems only. For 24 V applications, Vishay recommends SM8S33ATHE3/I (VWM = 33 V) or SM8S36ATHE3/I (VWM = 36 V), which provide matching surge ratings and thermal performance in the same DO-218AC package.
How is thermal performance affected if the metal heatsink is not soldered to PCB copper?
If the metal heatsink (anode/lead 2) of SM8S20ATHE3/I is not soldered to a minimum 100 mm² copper pour, thermal resistance rises significantly-RθJA may exceed 50 °C/W versus the specified RθJC = 0.90 °C/W. This causes rapid junction temperature rise during surge events, risking thermal runaway and permanent failure. Full heatsink soldering is mandatory for rated 6600 W operation.
Does SM8S20ATHE3/I meet ISO7637-2 Pulse 5a requirements out-of-the-box?
Yes-SM8S20ATHE3/I is explicitly validated to meet ISO7637-2 Pulse 5a (load dump) test conditions per Vishay documentation. Its 6600 W peak pulse power (10/1000 μs), 32.4 V clamping voltage at 204 A, and 175 °C junction rating ensure compliance when properly mounted with adequate PCB copper area and layout per Figure 2 in document 87734.
Why is SM8S20ATHE3/I marked "Not For New Designs"?
Vishay designates SM8S20ATHE3/I "Not For New Designs" because the HE3-series packaging has been superseded by the HM3 series (e.g., SM8S20AHM3), which features halogen-free molding compound and updated process controls. While SM8S20ATHE3/I remains fully functional and supported for existing designs, new projects should adopt HM3 variants for long-term supply assurance and environmental compliance.
SM8S20ATHE3/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):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 32.4V
- Current - Peak Pulse (10/1000µs):
- 204A
- Power - Peak Pulse:
- 6600W (6.6kW)
- 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
SM8S20ATHE3/I FAQ
1.How can I place an order for SM8S20ATHE3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SM8S20ATHE3/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 SM8S20ATHE3/I reliable?
The price and inventory of SM8S20ATHE3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM8S20ATHE3/I is usually 5 days.
3.What payment methods are accepted for SM8S20ATHE3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM8S20ATHE3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM8S20ATHE3/I?
SM8S20ATHE3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM8S20ATHE3/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 SM8S20ATHE3/I?
For technical support, including SM8S20ATHE3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM8S20ATHE3/I requirements.
6.How does Aetrix verify that SM8S20ATHE3/I is sourced from the original manufacturer or authorized distributors?
All SM8S20ATHE3/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 SM8S20ATHE3/I meets industry standards.
7.What is the process for return or replacement of SM8S20ATHE3/I?
All SM8S20ATHE3/I units undergo pre-shipment inspection (PSI). If there is an issue with SM8S20ATHE3/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 SM8S20ATHE3/I part is unused and in its original packaging.
Return procedure for SM8S20ATHE3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM8S20ATHE3/I Tags
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