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Vishay General Semiconductor - Diodes Division SM5S18AHE3_A/I
- Part No.:
- SM5S18AHE3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
SM5S18AHE3_A/I.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO218AB
- Quantity:
- Payment:
- Shipping:
Inventory:5,471
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Product details
Overview
SM5S18AHE3_A/I from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor (TVS) designed for automotive load dump protection. It features a 18.0 V stand-off voltage (VWM), 20.0–22.1 V breakdown voltage (VBR) at 5 mA, 3600 W peak pulse power (10/1000 μs), 123 V clamping voltage at 150 A, and AEC-Q101 qualification for under-hood electronics.
For engineers reviewing the SM5S18AHE3_A/I datasheet, SM5S18AHE3_A/I pinout, SM5S18AHE3_A/I application, or SM5S18AHE3_A/I equivalent, this device is selected for high-reliability 12 V automotive systems requiring ISO7637-2 compliance, TJ = 175 °C operation, low leakage (<10 μA at VWM), and DO-218AB package thermal performance with RθJM = 0.45 °C/W.
Technical Context
This TVS diode uses passivated anisotropic rectifier technology to deliver stable clamping under repetitive surge stress. Its unidirectional polarity, heatsink-anode configuration, and MSL Level 1 rating support automated SMT assembly on FR4 PCBs with 2 oz copper.
The device operates across –55 °C to +175 °C junction temperature, with thermal resistance junction-to-mount (RθJM) of 0.45 °C/W enabling effective heat transfer to metal chassis or heatsinks-critical for sustained load dump events in engine control units and body control modules.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18.0 V - Maximum continuous reverse operating voltage before conduction begins; sets system-level overvoltage trip threshold in 12 V automotive circuits. |
| VBR (min/typ/max) | 20.0 / 21.1 / 22.1 V at 5 mA - Confirmed breakdown range ensures reliable turn-on during transients while avoiding false triggering during normal battery ripple. |
| VC @ IPPM | 123 V at 150 A (10/1000 μs) - Clamping voltage defines maximum voltage seen by protected downstream ICs during worst-case surge. |
| PPPM (10/1000 μs) | 3600 W - Peak surge power handling capacity validated per ISO7637-2 Pulse 5a, supporting robust load dump immunity. |
| TJ max | +175 °C - Enables placement near high-temperature zones (e.g., powertrain ECUs) without derating concerns. |
| Polarity | Unidirectional - Anode connected to chassis/ground; cathode to protected line; suited for DC-biased automotive bus protection. |
| Package | DO-218AB - Metal heatsink package with matte tin-plated leads; provides low RθJM (0.45 °C/W) and meets UL 94 V-0 flammability. |
Pinout & Package
DO-218AB package features two terminals: Lead 1 (cathode) and Lead 2/metal heatsink (anode). The anode serves as both electrical terminal and thermal interface, requiring direct mounting to a thermally conductive plane or heatsink for optimal power dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Lead 1 (Cathode) | Protected line connection | Connected to the 12 V supply rail or signal line being safeguarded; carries surge current into the anode during clamping. |
| Lead 2 / Metal Heatsink (Anode) | Ground reference & thermal path | Must be soldered to a large copper pour or chassis ground; functions as primary heat sink and return path for surge current. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing-required for production ECUs. |
| Junction passivation | Optimized die passivation reduces parameter drift over time and improves long-term stability under high-temperature bias conditions. |
| MSL Level 1 (245 °C peak) | Enables standard reflow soldering without moisture sensitivity concerns-no baking required prior to assembly. |
| Low leakage ID ≤ 10 μA @ VWM | Minimizes standby power loss in always-on vehicle networks (e.g., CAN wake-up lines, LIN sensors). |
| ISO7637-2 compliant | Meets Pulse 5a (load dump) requirements up to 35 V, 400 ms duration-validated for 12 V system protection. |
Applications
| Engine Control Unit (ECU) Power Input | Body Control Module (BCM) Supply Rail |
|---|---|
Use Scenario: Protects microcontroller power rails from alternator load dump surges during battery disconnection events. IC Role / Device Role: Primary clamping element placed between battery feed and DC/DC input stage. Use Value: Limits transient voltage to ≤123 V, preventing damage to 36 V-rated input capacitors and LDO regulators. |
Use Scenario: Shields BCM logic supply from coupled transients generated by relay switching in lighting and door lock circuits. IC Role / Device Role: Secondary TVS on fused 12 V distribution branch feeding MCU and CAN transceivers. Use Value: Provides <10 μA leakage at 18 V, preserving low-power sleep mode integrity while sustaining 175 °C ambient operation. |
| Advanced Driver Assistance Systems (ADAS) Camera Power | Electric Power Steering (EPS) Motor Driver Stage |
Use Scenario: Safeguards image sensor and ISP power inputs against ignition-induced spikes and hot-swap transients. IC Role / Device Role: Unidirectional TVS mounted directly at camera module connector entry point. Use Value: Delivers 3600 W surge capability with 0.45 °C/W RθJM, enabling compact layout without external heatsink. |
Use Scenario: Protects gate drivers and current sense amplifiers from inductive kickback during motor phase commutation. IC Role / Device Role: High-energy clamping device placed across H-bridge supply rail and chassis ground. Use Value: Withstands 500 A IFSM (8.3 ms half-sine), ensuring survivability during repeated motor stall events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SM5S18AHM3_A/I | Same VWM/VBR/PPPM specs; HM3 suffix indicates halogen-free, RoHS-compliant, and AEC-Q101 qualified variant with improved whisker resistance (JESD 201 Class 2). | Identical use cases; preferred for new designs targeting enhanced material compliance and long-term tin whisker mitigation. | Select SM5S18AHM3_A/I for new designs where halogen-free content and extended whisker reliability are mandated. |
| SMAJ18A | Lower PPPM (400 W), smaller SMA package (RθJA = 60 °C/W), no AEC-Q101 qualification, and higher clamping voltage (32.4 V @ 12.9 A). | Limited to non-automotive, lower-energy applications such as industrial controls or consumer power supplies. | Use SMAJ18A only in cost-sensitive, non-automotive designs where 3600 W surge immunity and 175 °C operation are not required. |
Compared with SM5S18AHE3_A/I, SM5S18AHM3_A/I offers identical electrical performance with upgraded environmental compliance, while SMAJ18A trades significant surge capability and automotive qualification for footprint and cost reduction-making it unsuitable for load dump protection but viable for basic line filtering.
Availability
SM5S18AHE3_A/I is available at Aetrix Electronics and suitable for automotive ECU power protection, ADAS camera supply conditioning, and EPS motor driver surge suppression requiring stable component supply across extended temperature and high-reliability environments.
Supply support for SM5S18AHE3_A/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, rectifiers, and protection devices for automotive, industrial, and computing markets.
The SM5SxxA family was engineered specifically for automotive load dump protection, combining high-temperature junction capability (175 °C), ISO7637-2 compliance, and DO-218AB thermal performance to replace legacy axial and larger SMC packages.
FAQ
What is the maximum clamping voltage of the SM5S18AHE3_A/I at rated surge current?
The SM5S18AHE3_A/I has a maximum clamping voltage (VC) of 123 V when subjected to a 150 A peak pulse current with a 10/1000 μs waveform. This value is measured and guaranteed per the Vishay datasheet (Document Number 88382, page 2), and defines the upper voltage limit imposed on protected circuitry during standardized surge events.
Is the SM5S18AHE3_A/I qualified for automotive applications?
Yes, the SM5S18AHE3_A/I is AEC-Q101 qualified, as explicitly stated in the Vishay datasheet (page 1, FEATURES section and Ordering Information Table footnote 1). This qualification covers stress tests including temperature cycling, high-temperature reverse bias, and ESD, confirming suitability for production automotive electronics.
What does the "HE3" suffix mean in SM5S18AHE3_A/I?
The "HE3" suffix in SM5S18AHE3_A/I indicates RoHS-compliant, halogen-free construction with matte tin-plated leads that meet J-STD-002 and JESD 22-B102 solderability standards. The "H" denotes AEC-Q101 qualification, and "E3" confirms lead-free, non-halogen termination per Vishay's material categorization system.
Can SM5S18AHE3_A/I be used in bidirectional configurations?
No, the SM5S18AHE3_A/I is unidirectional only, as confirmed in the FEATURES section of the datasheet ("Available in unidirectional polarity only"). Its anode-is-heatsink construction and electrical characteristics are optimized for DC-biased protection; bidirectional operation requires a dedicated symmetric TVS like the SMBJ18CA.
What is the thermal resistance from junction to mount (RθJM) for SM5S18AHE3_A/I?
The SM5S18AHE3_A/I has a typical thermal resistance junction-to-mount (RθJM) of 0.45 °C/W, per the THERMAL CHARACTERISTICS table on page 3 of the Vishay datasheet. This low value reflects efficient heat transfer from the silicon die through the metal heatsink terminal to the PCB copper or chassis, critical for sustained surge duty cycles.
SM5S18AHE3_A/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-218AB
- Series:
- PAR®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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):
- 123A
- 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-218AB
SM5S18AHE3_A/I FAQ
1.How can I place an order for SM5S18AHE3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SM5S18AHE3_A/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 SM5S18AHE3_A/I reliable?
The price and inventory of SM5S18AHE3_A/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM5S18AHE3_A/I is usually 5 days.
3.What payment methods are accepted for SM5S18AHE3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM5S18AHE3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM5S18AHE3_A/I?
SM5S18AHE3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM5S18AHE3_A/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 SM5S18AHE3_A/I?
For technical support, including SM5S18AHE3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM5S18AHE3_A/I requirements.
6.How does Aetrix verify that SM5S18AHE3_A/I is sourced from the original manufacturer or authorized distributors?
All SM5S18AHE3_A/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 SM5S18AHE3_A/I meets industry standards.
7.What is the process for return or replacement of SM5S18AHE3_A/I?
All SM5S18AHE3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SM5S18AHE3_A/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 SM5S18AHE3_A/I part is unused and in its original packaging.
Return procedure for SM5S18AHE3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM5S18AHE3_A/I Tags
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