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Vishay General Semiconductor - Diodes Division SM8S18A-2HE3/2D
- Part No.:
- SM8S18A-2HE3/2D
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
SM8S18A-2HE3/2D.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO218AB
- Quantity:
- Payment:
- Shipping:
Inventory:2,029
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Product details
Overview
SM8S18A-2HE3/2D from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor in DO-218AB package, rated for 18.0 V stand-off voltage (VWM), 20.0–22.1 V breakdown voltage (VBR), and 6600 W peak pulse power (10/1000 μs). It delivers 226 A peak pulse current and clamps to 29.2 V at rated surge, designed specifically for automotive load dump protection in engine control units and body electronics.
For engineers reviewing the SM8S18A-2HE3/2D datasheet, SM8S18A-2HE3/2D pinout, SM8S18A-2HE3/2D application, or SM8S18A-2HE3/2D equivalent, key selection criteria include unidirectional polarity, 175 °C junction rating, AEC-Q101 qualification, low leakage (<10 μA at VWM), and thermal resistance of 0.90 °C/W (junction-to-case).
Technical Context
This TVS diode uses passivated anisotropic rectifier technology optimized for high-temperature stability and automotive-grade reliability. Its unidirectional configuration enables forward conduction during overvoltage events while maintaining low forward voltage drop (≤1.8 V at 100 A) and low reverse leakage (≤10 μA at 25 °C, ≤150 μA at 175 °C).
The device meets ISO 7637-2 surge requirements under defined test conditions and complies with MSL Level 1 per J-STD-020 (peak reflow 245 °C). Its DO-218AB package features a metal heatsink as anode terminal, enabling efficient thermal dissipation in high-power transient scenarios.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18.0 V - maximum reverse operating voltage before clamping begins |
| VBR (min/max) | 20.0 V / 22.1 V - breakdown occurs within this range at 5 mA test current |
| VC @ IPPM | 29.2 V - clamping voltage at 226 A peak pulse current (10/1000 μs) |
| PPPM (10/1000 μs) | 6600 W - peak surge power handling capability for standard automotive transients |
| TJ max. | 175 °C - extended junction temperature rating supports under-hood automotive use |
| RθJC | 0.90 °C/W - thermal resistance from junction to case enables effective heatsinking |
| Polarity | Unidirectional - anode-connected heatsink conducts forward during clamping |
Pinout & Package
Package: DO-218AB - surface-mount, thermally enhanced case with integral metal heatsink (anode terminal), UL 94 V-0 molding compound, matte tin-plated leads compliant with J-STD-002 and JESD 22-B102.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Lead 1 | Cathode | Standard cathode connection; reverse-biased during normal operation, conducts during overvoltage |
| Lead 2 / Metal Heatsink | Anode | Primary thermal path and electrical anode terminal; must be connected to system ground or low-impedance return |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronic systems requiring robust reliability and qualification traceability |
| Junction temperature up to 175 °C | Enables deployment in high-ambient environments such as engine compartments without derating |
| Low reverse leakage (≤10 μA @ 25 °C) | Minimizes standby power loss and avoids false triggering in low-power monitoring circuits |
| ISO 7637-2 compliance (varied by test condition) | Meets automotive transient immunity standards for load dump and inductive switching events |
| MSL Level 1 (245 °C peak) | Supports standard lead-free reflow assembly without moisture sensitivity concerns |
Applications
| Engine Control Unit (ECU) Protection | Body Control Module (BCM) |
|---|---|
Use Scenario: Protects microcontroller I/O and power rails from 12 V battery line transients during alternator load dump. IC Role / Device Role / Timing Role: Unidirectional TVS clamps reverse-polarity surges and absorbs 6600 W pulses to limit rail voltage to 29.2 V. Use Value: Prevents latch-up or permanent damage to 3.3 V/5 V logic and CAN transceivers downstream of the protected rail. | Use Scenario: Shields LIN bus interface and power management ICs from inductive kickback generated by door lock actuators and window motors. IC Role / Device Role / Timing Role: Fast-response clamping (ns-scale) limits transient duration and amplitude on shared 12 V supply lines. Use Value: Maintains communication integrity and prevents reset events during repeated actuator cycling in vehicle door modules. |
| Advanced Driver Assistance Systems (ADAS) Power Input | Start-Stop System Battery Interface |
Use Scenario: Guards camera module power inputs against voltage spikes during cold-crank and jump-start conditions. IC Role / Device Role / Timing Role: Absorbs 226 A peak current (10/1000 μs) while maintaining clamping below 30 V to protect image sensor bias rails. Use Value: Ensures uninterrupted video capture during engine restart cycles where supply dips and rebounds rapidly. | Use Scenario: Safeguards bidirectional DC-DC converter control circuitry during battery voltage reversal and regenerative braking surges. IC Role / Device Role / Timing Role: Withstands repetitive 175 °C junction temperature excursions and provides stable clamping across wide temperature range. Use Value: Extends functional lifetime of start-stop electronics by preventing thermal runaway during frequent high-current transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18A-E3/5AT | Lower PPPM (400 W), SMA package, 0.55 °C/W RθJC, 150 °C TJ max | Not AEC-Q101 qualified; limited to non-automotive industrial use | Select only for cost-sensitive, non-automotive applications with lower surge energy requirements |
| TPSMD18A | Same DO-218AB package, 6600 W PPPM, but 20.0–22.2 V VBR and 29.5 V VC; RoHS-compliant, not AEC-Q101 certified | Lacks automotive qualification; may require additional system-level validation for automotive deployment | Consider when AEC-Q101 is not mandated but DO-218AB thermal performance is required |
Compared with SMAJ18A-E3/5AT and TPSMD18A, the SM8S18A-2HE3/2D uniquely combines AEC-Q101 qualification, 175 °C operation, and 6600 W surge capability in a single DO-218AB device-enabling direct integration into production automotive ECUs without supplemental qualification testing.
Availability
SM8S18A-2HE3/2D is available at Aetrix Electronics and suitable for automotive ECU protection, body electronics safeguarding, and ADAS power input conditioning requiring stable component supply and long-term lifecycle support.
Supply support for SM8S18A-2HE3/2D 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, TVS devices, and optoelectronics with emphasis on reliability, thermal performance, and automotive qualification.
The SM8SxxA series is engineered for high-energy transient suppression in harsh automotive environments, targeting load dump, inductive switching, and ISO 7637-2 compliance without external heatsinking.
FAQ
What is the clamping voltage of the SM8S18A-2HE3/2D at its rated peak pulse current?
The SM8S18A-2HE3/2D clamps to a maximum of 29.2 V at its rated peak pulse current of 226 A (10/1000 μs waveform). This value is measured under standardized test conditions at TC = 25 °C and defines the upper voltage limit imposed on protected circuitry during a full-power transient event. The SM8S18A-2HE3/2D maintains this clamping performance across its operational temperature range, supporting robust design margins in automotive power systems.
Is the SM8S18A-2HE3/2D qualified for automotive applications?
Yes, the SM8S18A-2HE3/2D is AEC-Q101 qualified and explicitly designed for automotive use. It meets ISO 7637-2 surge requirements under defined test conditions and operates reliably from −55 °C to +175 °C. Its DO-218AB package, matte tin plating, and JESD 201 Class 2 whisker resistance further confirm its suitability for production automotive electronics. The SM8S18A-2HE3/2D is commonly deployed in engine control units and body control modules.
What is the polarity configuration of the SM8S18A-2HE3/2D?
The SM8S18A-2HE3/2D is unidirectional, with the metal heatsink serving as the anode terminal and Lead 1 as the cathode. This configuration allows forward conduction during overvoltage events, enabling efficient clamping of positive transients on grounded systems. Polarity must be observed during PCB layout-the anode (heatsink) must connect to the protected line's reference or ground plane. The SM8S18A-2HE3/2D does not support bidirectional operation.
How does the thermal performance of the SM8S18A-2HE3/2D compare to smaller-package TVS diodes?
The SM8S18A-2HE3/2D achieves a typical junction-to-case thermal resistance (RθJC) of 0.90 °C/W-significantly lower than SMA- or SMC-packaged alternatives (e.g., ~3–5 °C/W). This enables higher sustained power dissipation and better transient energy absorption without external heatsinking. When mounted on a copper pad ≥100 mm², the SM8S18A-2HE3/2D sustains full 6600 W surge capability. Smaller packages cannot replicate this thermal performance.
What packaging format is used for the SM8S18A-2HE3/2D?
The SM8S18A-2HE3/2D ships in 13-inch plastic tape and reel format with 750 units per reel (package code "2D"). The anode (metal heatsink) faces the sprocket hole, ensuring correct orientation during automated placement. The HE3 suffix indicates RoHS compliance and AEC-Q101 qualification. This packaging supports high-volume SMT assembly and is compatible with standard pick-and-place equipment used in automotive electronics manufacturing.
SM8S18A-2HE3/2D 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):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 29.2V
- Current - Peak Pulse (10/1000µs):
- 226A
- 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-218AB
SM8S18A-2HE3/2D FAQ
1.How can I place an order for SM8S18A-2HE3/2D through Aetrix?
Please submit a Request for Quotation (RFQ) for SM8S18A-2HE3/2D 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 SM8S18A-2HE3/2D reliable?
The price and inventory of SM8S18A-2HE3/2D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM8S18A-2HE3/2D is usually 5 days.
3.What payment methods are accepted for SM8S18A-2HE3/2D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM8S18A-2HE3/2D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM8S18A-2HE3/2D?
SM8S18A-2HE3/2D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM8S18A-2HE3/2D 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 SM8S18A-2HE3/2D?
For technical support, including SM8S18A-2HE3/2D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM8S18A-2HE3/2D requirements.
6.How does Aetrix verify that SM8S18A-2HE3/2D is sourced from the original manufacturer or authorized distributors?
All SM8S18A-2HE3/2D 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 SM8S18A-2HE3/2D meets industry standards.
7.What is the process for return or replacement of SM8S18A-2HE3/2D?
All SM8S18A-2HE3/2D units undergo pre-shipment inspection (PSI). If there is an issue with SM8S18A-2HE3/2D, 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 SM8S18A-2HE3/2D part is unused and in its original packaging.
Return procedure for SM8S18A-2HE3/2D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM8S18A-2HE3/2D Tags
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