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Vishay General Semiconductor - Diodes Division SM5S18CAHM3/I
- Part No.:
- SM5S18CAHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
SM5S18CAHM3/I.pdf
- Description:
- 3600 W BI-DIRECTIONAL TVS IS DO-
- Quantity:
- Payment:
- Shipping:
Inventory:2,995
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Product details
Overview
SM5S18CAHM3/I from Vishay General Semiconductor is a bidirectional surface-mount PAR® transient voltage suppressor (TVS) designed for automotive load dump protection in 12 V systems. It features a 20.0–22.1 V breakdown voltage (VBR), 18.0 V stand-off voltage (VWM), 29.2 V maximum clamping voltage (VC) at 123 A peak pulse current, and 3600 W peak pulse power (10/1000 µs). Its DO-218AC package supports high-reliability underhood applications.
For engineers reviewing the SM5S18CAHM3/I datasheet, SM5S18CAHM3/I pinout, SM5S18CAHM3/I application, or SM5S18CAHM3/I equivalent, this device delivers AEC-Q101 qualification, TJ = 175 °C operation, ISO 7637-2 compliance, low leakage (<10 µA at VWM), and halogen-free RoHS-compliant construction - critical for automotive electronics design validation and long-term supply assurance.
Technical Context
This TVS diode operates as a bidirectional clamping device with no polarity marking, enabling symmetric surge suppression across power rails. Its junction-to-mount thermal resistance of 0.45 °C/W and DO-218AC metal-heatsink terminal structure allow efficient heat transfer to PCB copper, supporting sustained 5 W power dissipation at TA = 25 °C on FR4.
The device meets ISO 16750-2 surge test conditions for automotive environments and exhibits stable clamping performance up to +175 °C junction temperature. Its 10/1000 µs waveform rating of 3600 W and 10/10,000 µs rating of 2200 W (for 12CA–20CA variants) confirm suitability for both fast transients and longer-duration load dump events.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 20.0 / 21.1 / 22.1 V - ensures reliable triggering above system nominal voltage while avoiding false conduction during normal 12 V rail fluctuations |
| VWM | 18.0 V - defines maximum continuous reverse operating voltage without significant leakage, compatible with 12 V automotive battery systems |
| VC @ IPPM | 29.2 V at 123 A - limits downstream IC voltage stress during 3600 W transient events, protecting 30 V-rated components |
| IPPM (10/1000 µs) | 123 A - quantifies maximum surge current handling capability under standard automotive test waveform |
| PPPM | 3600 W - peak pulse power rating confirming robustness against ISO 7637-2 Pulse 5a/b load dump surges |
| TJ max | +175 °C - enables underhood placement without derating in high-temperature engine compartments |
| Leakage @ VWM | <10 µA at 25 °C - minimizes standby power loss and avoids interference with low-power sensor circuits |
Pinout & Package
Package: DO-218AC - surface-mount, bidirectional, metal-heatsink case with matte tin-plated terminals solderable per J-STD-002 and JESD 22-B102; meets MSL Level 1 (245 °C peak reflow) and JESD 201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Lead 1 | Anode (bidirectional terminal) | One side of symmetrical PN junction; connects to protected line (e.g., battery rail); no cathode band marking required |
| Lead 2 / Metal Heatsink | Cathode / Thermal Path | Integrated metal slug serving as both second terminal and primary thermal conduction path to PCB copper pour or heatsink pad |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing - required for front-end power protection in ECUs and ADAS modules |
| DO-218AC metal-heatsink package | Enables 0.45 °C/W junction-to-mount thermal resistance - reduces thermal stress during repeated surge events and extends lifetime in high-ambient environments |
| ISO 7637-2 & ISO 16750-2 compliance | Meets automotive surge immunity standards for load dump (Pulse 5) and supply voltage variation - eliminates need for additional external filtering in OEM designs |
| Bidirectional clamping | Protects against both positive and negative transients without polarity sensitivity - simplifies layout and eliminates risk of incorrect orientation during assembly |
| Halogen-free, RoHS-compliant (M3 suffix) | Fulfills global environmental regulations and supports lead-free reflow processes without compromising surge performance or thermal stability |
Applications
| Automotive Load Dump Protection | Industrial Power Supply Clamping |
|---|---|
|
Use Scenario: Protecting engine control units (ECUs) and body control modules (BCMs) from 12 V battery line transients during alternator load dump events. IC Role / Device Role / Timing Role: Primary clamping element placed between battery rail and DC/DC converter input, absorbing >3 kW pulses within microseconds. Use Value: Limits voltage to ≤29.2 V during 123 A surges, preventing damage to 30 V-rated regulators and microcontrollers without requiring series impedance. |
Use Scenario: Safeguarding programmable logic controllers (PLCs) and motor drives from switching-induced transients on 24 V industrial power buses. IC Role / Device Role / Timing Role: Standoff voltage (18.0 V) aligns with 24 V nominal systems; clamps fast-rising spikes before they propagate to sensitive I/O circuitry. Use Value: Delivers 2200 W (10/10,000 µs) energy absorption - sufficient for repetitive inductive kickback from solenoid valves and contactors. |
| Automotive Infotainment Power Rail | Telematics Module Surge Suppression |
|
Use Scenario: Securing USB-C PD and display power supplies in head units against battery voltage reversals and jump-start surges. IC Role / Device Role / Timing Role: Bidirectional operation handles both positive overvoltage and negative reverse-battery events without polarity constraints. Use Value: Low leakage (<10 µA) prevents quiescent current drain on always-on 12 V rails, preserving battery life in parked vehicle modes. |
Use Scenario: Shielding LTE/C-V2X communication modules from conducted EMI and electrostatic discharge coupled through vehicle antenna cables and CAN lines. IC Role / Device Role / Timing Role: Mounted at board-level power entry point to shunt transients before reaching PMICs and RF front-ends. Use Value: 175 °C junction rating ensures uninterrupted operation during prolonged high-temperature cabin conditions (>85 °C ambient). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18CA | DO-214AC package; lower PPPM (400 W); VC = 29.2 V at 13.9 A; RθJA = 110 °C/W | Limited to low-energy transients; unsuitable for ISO 7637-2 Pulse 5; used in consumer-grade 12 V accessories | Select SMAJ18CA only for cost-sensitive non-automotive applications where surge energy is <500 W and thermal margin is not constrained. |
| TPSMD18CA | DO-218AC package; same VWM/VC; PPPM = 3000 W (10/1000 µs); AEC-Q101 qualified; slightly higher VBR tolerance (±6 %) | Lower peak power handling than SM5S18CAHM3/I; acceptable for less severe load dump profiles (e.g., mild hybrid vehicles) | Choose TPSMD18CA when supply chain diversification is needed and full 3600 W capability is not required - retains same footprint and thermal interface. |
Compared with SMAJ18CA and TPSMD18CA, the SM5S18CAHM3/I provides superior surge robustness (3600 W vs. 400 W / 3000 W), lower thermal resistance (0.45 °C/W vs. ~110 °C/W / ~0.55 °C/W), and tighter VBR tolerance (±5 %), making it the preferred choice for demanding automotive front-end protection where reliability and thermal performance are critical.
Availability
SM5S18CAHM3/I is available at Aetrix Electronics and suitable for automotive ECU protection, industrial PLC power rails, and telematics module surge suppression requiring stable component supply across multi-year production cycles.
Supply support for SM5S18CAHM3/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 SM5SxxCA family is engineered specifically for high-energy automotive transient suppression, combining AEC-Q101 qualification, DO-218AC thermal efficiency, and ISO 7637-2 compliance to address stringent OEM front-end protection requirements.
FAQ
What is the maximum clamping voltage of the SM5S18CAHM3/I under a 10/1000 µs surge?
The SM5S18CAHM3/I has a maximum clamping voltage (VC) of 29.2 V when subjected to its rated peak pulse current of 123 A under the 10/1000 µs waveform. This value is measured per Figure 4 in the Vishay datasheet (Document Number 98458) and ensures downstream components see voltage limited to this level during standardized automotive surge events. The SM5S18CAHM3/I maintains this clamping performance across its full operating temperature range.
Is the SM5S18CAHM3/I suitable for use in AEC-Q101-compliant automotive designs?
Yes, the SM5S18CAHM3/I is explicitly AEC-Q101 qualified, as confirmed by the "H" in its part number suffix and documented in Vishay's ordering information table. It undergoes rigorous stress testing including temperature cycling, high-temperature reverse bias, and ESD verification - meeting the reliability requirements for under-hood and chassis-mounted automotive electronics. The SM5S18CAHM3/I is certified for TJ = -55 °C to +175 °C operation.
Does the SM5S18CAHM3/I require polarity-aware PCB layout?
No, the SM5S18CAHM3/I is a bidirectional TVS diode with no cathode band marking and symmetrical electrical characteristics. Its DO-218AC package has identical terminal behavior in either orientation, eliminating risk of misplacement during automated assembly. This feature simplifies PCB routing and reduces manufacturing defects - a key advantage of the SM5S18CAHM3/I over unidirectional alternatives that mandate strict anode/cathode alignment.
What is the thermal resistance from junction to mount (RθJM) for the SM5S18CAHM3/I?
The SM5S18CAHM3/I has a typical junction-to-mount thermal resistance (RθJM) of 0.45 °C/W, as specified in the Thermal Characteristics table of the Vishay datasheet. This low value is enabled by its integrated metal heatsink terminal (Lead 2), which provides direct thermal conduction to the PCB copper pour or external heatsink. This parameter is critical for calculating steady-state temperature rise during continuous 5 W power dissipation - a key design input for the SM5S18CAHM3/I in thermally constrained layouts.
Which international surge standards does the SM5S18CAHM3/I meet?
The SM5S18CAHM3/I meets both ISO 7637-2 (for automotive electrical disturbances from conduction and coupling) and ISO 16750-2 (for environmental conditions and testing - electrical loads) surge specifications, as stated in the Features section of the Vishay datasheet. These certifications validate its performance against standardized load dump, supply voltage fluctuation, and transient burst tests required by major automotive OEMs - confirming the SM5S18CAHM3/I's readiness for Tier 1 supplier qualification programs.
SM5S18CAHM3/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:
- -
- Bidirectional Channels:
- 1
- 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
SM5S18CAHM3/I FAQ
1.How can I place an order for SM5S18CAHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SM5S18CAHM3/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 SM5S18CAHM3/I reliable?
The price and inventory of SM5S18CAHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM5S18CAHM3/I is usually 5 days.
3.What payment methods are accepted for SM5S18CAHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM5S18CAHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM5S18CAHM3/I?
SM5S18CAHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM5S18CAHM3/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 SM5S18CAHM3/I?
For technical support, including SM5S18CAHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM5S18CAHM3/I requirements.
6.How does Aetrix verify that SM5S18CAHM3/I is sourced from the original manufacturer or authorized distributors?
All SM5S18CAHM3/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 SM5S18CAHM3/I meets industry standards.
7.What is the process for return or replacement of SM5S18CAHM3/I?
All SM5S18CAHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SM5S18CAHM3/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 SM5S18CAHM3/I part is unused and in its original packaging.
Return procedure for SM5S18CAHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM5S18CAHM3/I Tags
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