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Vishay General Semiconductor - Diodes Division SM5S18A-E3/2D
- Part No.:
- SM5S18A-E3/2D
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
SM5S18A-E3/2D.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO218AB
- Quantity:
- Payment:
- Shipping:
Inventory:2,703
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Product details
Overview
SM5S18A-E3/2D from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor (TVS) diode designed for automotive load dump protection. It features a 18.0 V stand-off voltage (VWM), 29.2 V clamping voltage at 123 A peak pulse current (10/1000 µs), 3600 W peak pulse power, 175 °C junction temperature rating, and DO-218AB package with anode-heatsink polarity.
For engineers reviewing the SM5S18A-E3/2D datasheet, SM5S18A-E3/2D pinout, SM5S18A-E3/2D application, or SM5S18A-E3/2D equivalent, this device is selected for high-reliability 12 V automotive power rail surge suppression where low leakage (<10 µA at VWM), AEC-Q101 qualification, and ISO7637-2 compliance are mandatory design requirements.
Technical Context
This TVS diode operates as a unidirectional clamping device in series with the anode connected to the protected line and cathode grounded-leveraging silicon avalanche breakdown to limit transients. Its DO-218AB package integrates a metal heatsink as the anode terminal, enabling direct thermal coupling to PCB copper for sustained 5 W power dissipation at TC = 25 °C.
The device meets AEC-Q101 stress testing for automotive use and delivers stable performance up to TJ = 175 °C. Its 1.0 °C/W junction-to-case thermal resistance supports robust load dump handling under real-world under-hood thermal conditions without derating below 125 °C case temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18.0 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC bias window for 12 V automotive systems. |
| VBR (min/max) | 20.0 V / 22.1 V - Breakdown occurs within this range at 5 mA test current; ensures predictable turn-on margin above VWM. |
| VC @ IPPM | 29.2 V - Clamping voltage at 123 A (10/1000 µs); limits worst-case transient voltage seen by downstream ICs. |
| PPPM (10×1000 µs) | 3600 W - Peak pulse power capability; sustains ISO7637-2 Load Dump Pulse 5a (12 V system) without failure. |
| ID @ VWM | <10 µA - Reverse leakage at rated stand-off; minimizes quiescent power loss and avoids false triggering in low-current circuits. |
| TJ max. | 175 °C - Maximum junction temperature; enables operation in engine compartment environments without thermal shutdown. |
| RθJC | 1.0 °C/W - Junction-to-case thermal resistance; allows accurate thermal design when mounted on ≥1 in² 2 oz copper pad. |
Pinout & Package
Package: DO-218AB - Surface-mount molded case with integral metal heatsink acting as Terminal 1 (Anode); meets UL 94 V-0; RoHS-compliant matte tin plating; MSL Level 1 (245 °C reflow).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Terminal 1 (Metal Heatsink) | Anode | Primary current entry point during clamping; must be soldered to large copper area for thermal management and low-inductance path. |
| Terminal 2 (Lead) | Cathode | Connected to system ground; completes clamping path; layout must minimize trace inductance to preserve response speed. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD per JESD47; eliminates need for additional qualification testing. |
| Junction passivated anisotropic rectifier technology | Enables stable 175 °C operation and low leakage drift over lifetime; critical for extended vehicle service life. |
| Meets ISO7637-2 surge specification | Guarantees survivability against standardized automotive load dump and inductive switching transients without degradation. |
| MSL Level 1 rating | Supports standard SMT reflow profiles up to 245 °C peak without moisture-induced damage or popcorn effect. |
| Low forward voltage drop | VF ≤ 2.0 V at 100 A (8.3 ms half-sine); reduces conduction losses during high-current surge events. |
Applications
| Automotive Engine Control Unit (ECU) | Body Control Module (BCM) |
|---|---|
Use Scenario: Protecting microcontroller power inputs from alternator load dump spikes during battery disconnect/reconnect events. IC Role / Device Role / Timing Role: Unidirectional clamping TVS placed between battery feed and LDO input, absorbing >3 kW pulses within nanoseconds. Use Value: Prevents latch-up or permanent damage to 5 V/3.3 V regulators and MCU cores while maintaining <10 µA standby leakage. | Use Scenario: Safeguarding LIN bus transceiver power rails against inductive kickback from door lock actuators and mirror motors. IC Role / Device Role / Timing Role: Standoff-rated TVS on 12 V supply line upstream of local DC/DC converter, clamping transients before they propagate to communication ICs. Use Value: Ensures uninterrupted LIN communication during repeated actuator switching cycles, validated per ISO7637-2 Pulse 1 and 2b. |
| Advanced Driver Assistance Systems (ADAS) Camera Module | Electric Power Steering (EPS) Control Unit |
Use Scenario: Shielding image sensor and ISP power supplies from ignition noise and alternator ripple in front-end camera assemblies. IC Role / Device Role / Timing Role: Primary overvoltage clamp on 12 V input stage, coordinated with ceramic bulk capacitance to suppress sub-100 ns fast transients. Use Value: Maintains clean analog supply for CMOS image sensors, eliminating visual artifacts caused by voltage overshoot exceeding 29.2 V. | Use Scenario: Securing motor driver gate supply and MCU VDD against high-energy transients generated by brushless motor commutation. IC Role / Device Role / Timing Role: High-power TVS on main 12 V rail feeding H-bridge pre-drivers and current sense amplifiers. Use Value: Withstands repetitive 3600 W surges without parameter shift, preserving functional safety integrity per ISO 26262 ASIL-B requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18A-E3/5BT | DO-214AC (SMA) package; lower PPPM (400 W); higher VC (29.2 V same, but at only 12.9 A); RθJC ≈ 50 °C/W vs. 1.0 °C/W. | Not suitable for load dump; limited to low-energy ESD and inductive spikes; requires larger board area for thermal relief. | Select SMAJ18A-E3/5BT only for cost-sensitive non-automotive consumer applications with <500 W surge exposure. |
| TPSMD18A | DO-218AB package; same VWM/VC; lower PPPM (3300 W); AEC-Q101 qualified; slightly higher ID (25 µA @ VWM). | Acceptable for most 12 V automotive modules except high-duty-cycle EPS or starter motor interfaces. | Choose TPSMD18A when supply chain diversification is needed and 3300 W peak power suffices for the specific load profile. |
Compared with SM5S18A-E3/2D, SMAJ18A-E3/5BT offers lower cost but cannot handle automotive load dump energy, while TPSMD18A provides identical form factor and qualification with modestly reduced surge capacity-making SM5S18A-E3/2D the optimal choice for high-reliability 12 V power rail protection demanding full 3600 W capability.
Availability
SM5S18A-E3/2D is available at Aetrix Electronics and suitable for automotive engine control units, body control modules, ADAS camera systems, and electric power steering units requiring stable component supply across long production lifecycles.
Supply support for SM5S18A-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, optoelectronics, and passive components for automotive, industrial, and computing markets.
The SM5SxxA family is engineered specifically for automotive-grade transient suppression, emphasizing AEC-Q101 qualification, 175 °C operation, and ISO7637-2 compliance in ruggedized DO-218AB packaging.
FAQ
What is the clamping voltage of the SM5S18A-E3/2D and under what test condition is it specified?
The SM5S18A-E3/2D has a maximum clamping voltage (VC) of 29.2 V, measured at a peak pulse current (IPPM) of 123 A using the standard 10/1000 µs double-exponential waveform. This value is guaranteed across the full operating temperature range and reflects worst-case voltage limiting during automotive load dump events.
Is the SM5S18A-E3/2D suitable for bidirectional transient protection?
No, the SM5S18A-E3/2D is unidirectional only. Its electrical characteristics-including breakdown voltage, clamping behavior, and polarity marking-are defined for reverse-biased operation with the metal heatsink as the anode. For bidirectional protection, a dedicated symmetric TVS like SMBJ18CA would be required instead of SM5S18A-E3/2D.
What does the "-E3/2D" suffix indicate in SM5S18A-E3/2D?
The "-E3" suffix denotes RoHS-compliant, matte tin-plated terminals qualified to JESD201 Class 2 whisker resistance, while "/2D" specifies packaging in 13-inch plastic tape and reel with 750 units per reel and anode orientation toward the sprocket hole-ensuring correct automated placement and thermal mounting alignment for SM5S18A-E3/2D.
How does the DO-218AB package of the SM5S18A-E3/2D improve thermal performance compared to SMA or SMC packages?
The DO-218AB package integrates a large metal heatsink as Terminal 1 (anode), achieving a junction-to-case thermal resistance (RθJC) of just 1.0 °C/W-over 40× better than typical SMA packages (~50 °C/W). This allows SM5S18A-E3/2D to dissipate 5 W continuously when properly mounted, making it uniquely capable of surviving repeated automotive load dump pulses without thermal runaway.
Does the SM5S18A-E3/2D meet ISO7637-2, and which test pulses is it validated for?
Yes, the SM5S18A-E3/2D meets ISO7637-2 requirements for automotive transient immunity. It is validated for Pulse 5a (load dump) with 12 V system voltage, delivering full 3600 W peak power handling. The device also supports Pulse 1 (inductive switch-off) and Pulse 2b (supply disconnection) due to its low clamping voltage and fast response time-key for robust SM5S18A-E3/2D deployment in vehicle ECUs.
SM5S18A-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):
- 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:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-218AB
SM5S18A-E3/2D FAQ
1.How can I place an order for SM5S18A-E3/2D through Aetrix?
Please submit a Request for Quotation (RFQ) for SM5S18A-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 SM5S18A-E3/2D reliable?
The price and inventory of SM5S18A-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 SM5S18A-E3/2D is usually 5 days.
3.What payment methods are accepted for SM5S18A-E3/2D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM5S18A-E3/2D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM5S18A-E3/2D?
SM5S18A-E3/2D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM5S18A-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 SM5S18A-E3/2D?
For technical support, including SM5S18A-E3/2D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM5S18A-E3/2D requirements.
6.How does Aetrix verify that SM5S18A-E3/2D is sourced from the original manufacturer or authorized distributors?
All SM5S18A-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 SM5S18A-E3/2D meets industry standards.
7.What is the process for return or replacement of SM5S18A-E3/2D?
All SM5S18A-E3/2D units undergo pre-shipment inspection (PSI). If there is an issue with SM5S18A-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 SM5S18A-E3/2D part is unused and in its original packaging.
Return procedure for SM5S18A-E3/2D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM5S18A-E3/2D Tags
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