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Vishay General Semiconductor - Diodes Division SM8S12AHM3/I
- Part No.:
- SM8S12AHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AC
- Datasheet:
-
SM8S12AHM3/I.pdf
- Description:
- TVS DIODE 12VWM 19.9VC DO218AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,701
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Product details
Overview
SM8S12AHM3/I from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor in DO-218AB package, rated for 12 V stand-off voltage (VWM), 14.0 V nominal breakdown voltage (VBR), 6600 W peak pulse power (10/1000 μs), and 175 °C junction temperature-designed for automotive load dump protection in engine control units and body electronics.
For engineers reviewing the SM8S12AHM3/I datasheet, SM8S12AHM3/I pinout, SM8S12AHM3/I application, or SM8S12AHM3/I equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, thermal resistance (RθJM = 0.35 °C/W), clamping behavior (VC = 19.9 V at IPPM), and DO-218AB mechanical interface details required for robust overvoltage design in high-reliability automotive systems.
Technical Context
The SM8S12AHM3/I uses passivated anisotropic rectifier technology to achieve low leakage (<10 μA at VWM) and low forward voltage drop (VF ≤ 1.8 V at 100 A), enabling efficient clamping during fast transients. Its unidirectional polarity and heatsink-anode configuration support direct mounting to metal chassis for enhanced thermal dissipation.
It meets ISO 7637-2 surge requirements under defined test conditions and complies with MSL Level 1 (peak reflow 245 °C), making it suitable for automated SMT assembly in automotive-grade production. The device's TJ max of 175 °C and αT = 0.074 %/°C temperature coefficient ensure stable VBR across extended temperature ranges.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12 V - Maximum continuous reverse operating voltage before significant conduction begins; defines system bus voltage compatibility. |
| VBR (nom) | 14.0 V - Voltage at which device enters avalanche breakdown at 5 mA; ensures predictable turn-on margin above VWM. |
| VC @ IPPM | 19.9 V - Clamped voltage at 332 A peak pulse current (10/1000 μs); determines maximum stress on protected downstream ICs. |
| PPPM (10/1000 μs) | 6600 W - Peak transient energy handling capacity; supports high-energy load dump events per ISO 7637-2. |
| RθJM | 0.35 °C/W - Junction-to-mount thermal resistance; enables accurate thermal modeling when mounted to heatsink or chassis. |
| TJ max | +175 °C - Maximum allowable junction temperature; validates suitability for under-hood automotive environments. |
| AEC-Q101 | Qualified - Certified for automotive reliability including HTGB, HTRB, and temperature cycling; required for ECU and ADAS modules. |
Pinout & Package
Package: DO-218AB - molded surface-mount case with matte tin-plated leads, UL 94 V-0 flammability rating, and anode-connected metal heatsink tab for low-inductance, high-current transient path and thermal conduction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Heatsink Tab) | Main current return path during clamping | Electrically and thermally connected to PCB copper pour or chassis; must be soldered for full surge rating and thermal performance. |
| Cathode (Lead 1) | Transient voltage sensing and clamping node | Connected to protected line (e.g., battery rail); carries full IPPM during surge event; requires low-inductance layout. |
Key Features
| Feature | Design Value |
|---|---|
| Junction passivation optimized design | Enables stable leakage <10 μA at VWM and 175 °C, critical for low-power always-on automotive modules. |
| DO-218AB package with metal heatsink | Provides RθJM = 0.35 °C/W and supports 700 A IFSM surge, enabling compact placement near high-energy sources like alternators. |
| AEC-Q101 qualification | Validates reliability for automotive applications including engine control, lighting, and infotainment without derating. |
| ISO 7637-2 compliance (load dump) | Guarantees operation under 12 V system load dump pulses up to 35 V/10 ms, per automotive OEM requirements. |
| MSL Level 1 rating | Allows standard SMT reflow profile (peak 245 °C) without moisture sensitivity concerns or baking preconditioning. |
Applications
| Engine Control Unit (ECU) Power Input Protection | Automotive Lighting Module Surge Suppression |
|---|---|
|
Use Scenario: Protects microcontroller and CAN transceiver power rails from alternator load dump transients during battery disconnect. IC Role / Device Role / Timing Role: Unidirectional TVS clamps 35 V/10 ms load dump spikes to ≤19.9 V within nanoseconds, preserving downstream logic supply integrity. Use Value: Prevents reset or latch-up of 5 V/3.3 V regulators by limiting transient overshoot below their absolute maximum ratings. |
Use Scenario: Shields LED driver ICs and current-sense amplifiers from switching transients generated by high-side MOSFETs in headlamp modules. IC Role / Device Role / Timing Role: Fast-response TVS absorbs 6600 W surges with <1 ns response time, maintaining stable bias for analog feedback loops. Use Value: Eliminates need for oversized input capacitors and reduces board space by 30% versus discrete RC snubber + Zener solutions. |
| Body Control Module (BCM) LIN Bus Protection | Start-Stop System Battery Monitoring Circuit |
|
Use Scenario: Guards LIN transceiver pins against ESD and inductive kickback from solenoid actuators (door locks, trunk latches). IC Role / Device Role / Timing Role: Low-leakage (<10 μA) unidirectional clamp avoids signal distortion on 19.2 kbps LIN bus while surviving 8 kV contact ESD. Use Value: Maintains bus signal integrity without adding series resistance or capacitance that would degrade rise/fall times. |
Use Scenario: Safeguards precision voltage dividers and ADC inputs monitoring 12 V battery voltage during cranking and regenerative braking events. IC Role / Device Role / Timing Role: Stable VBR (±5%) and low TC (0.074 %/°C) ensure consistent clamping across -40 °C to +150 °C ambient. Use Value: Enables single-point calibration over full temperature range, reducing factory test time and BOM cost. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12AHE3/A | Lower PPPM (400 W), DO-214AC package, RθJM not specified, no AEC-Q101 qualification | Suitable for consumer-grade 12 V supplies; insufficient for automotive load dump per ISO 7637-2 | Select SMAJ12AHE3/A only for cost-sensitive non-automotive designs where surge energy is <500 W. |
| SM8S12AHE3/A | Same electrical specs but industry-grade (no 'H' suffix); lacks AEC-Q101 qualification and MSL Level 1 reflow rating | Acceptable for industrial controls with controlled assembly environment; not approved for automotive production | Choose SM8S12AHE3/A if AEC-Q101 is not mandated and reflow profile is tightly controlled. |
Compared with SMAJ12AHE3/A and SM8S12AHE3/A, the SM8S12AHM3/I delivers 16.5× higher surge power handling, certified automotive reliability, and validated thermal performance for chassis-mounted deployment-making it the sole option meeting OEM Tier-1 requirements for under-hood 12 V rail protection.
Availability
SM8S12AHM3/I is available at Aetrix Electronics and suitable for automotive engine control units, body electronics modules, and start-stop system battery monitoring circuits requiring stable component supply, long-term lifecycle assurance, and AEC-Q101-compliant sourcing.
Supply support for SM8S12AHM3/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 SM8SxxA family was engineered specifically for high-energy automotive transients, emphasizing AEC-Q101 qualification, DO-218AB thermal efficiency, and ISO 7637-2 compliance-targeting ECU, BCM, and ADAS power rail protection.
FAQ
What is the clamping voltage of the SM8S12AHM3/I at its rated peak pulse current?
The SM8S12AHM3/I has a maximum clamping voltage (VC) of 19.9 V at its rated peak pulse current of 332 A under the 10/1000 μs waveform. This value is measured per JEDEC standards and ensures protected downstream components remain below their absolute maximum voltage ratings during surge events. The SM8S12AHM3/I maintains this clamping performance across its full operating temperature range.
Is the SM8S12AHM3/I qualified for automotive applications?
Yes, the SM8S12AHM3/I is AEC-Q101 qualified and rated for operation from -55 °C to +175 °C. It meets ISO 7637-2 load dump requirements and is MSL Level 1 compliant-making it suitable for engine control units, body control modules, and other under-hood automotive systems. The 'H' in SM8S12AHM3/I explicitly denotes AEC-Q101 qualification.
What does the 'M3' suffix indicate in SM8S12AHM3/I?
The 'M3' suffix in SM8S12AHM3/I specifies packaging: 13-inch diameter plastic tape and reel, with anode oriented toward the sprocket hole. This format supports high-speed pick-and-place assembly and is standardized across Vishay's DO-218AB product line. The '/I' denotes the preferred package code per Vishay's ordering matrix.
How does the DO-218AB package of the SM8S12AHM3/I improve thermal performance?
The DO-218AB package of the SM8S12AHM3/I integrates a metal heatsink tab directly connected to the anode, achieving a junction-to-mount thermal resistance (RθJM) of 0.35 °C/W. When soldered to a large copper area or chassis, this enables effective heat extraction during repetitive surges-critical for sustaining 6600 W peak power without thermal runaway. Standard DO-214 packages lack this thermal path.
Can the SM8S12AHM3/I replace older SM8S12A variants in existing designs?
Yes, the SM8S12AHM3/I is a direct replacement for SM8S12AHE3/A and SM8S12AHE3/I in terms of electrical specs and footprint, but adds AEC-Q101 qualification and MSL Level 1 reflow capability. No PCB changes are required; however, designers should verify thermal mounting and confirm that the 'H' grade meets their automotive qualification requirements before migration.
SM8S12AHM3/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-218AC
- Series:
- PAR®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 19.9V
- Current - Peak Pulse (10/1000µs):
- 332A
- 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
SM8S12AHM3/I FAQ
1.How can I place an order for SM8S12AHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SM8S12AHM3/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 SM8S12AHM3/I reliable?
The price and inventory of SM8S12AHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM8S12AHM3/I is usually 5 days.
3.What payment methods are accepted for SM8S12AHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM8S12AHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM8S12AHM3/I?
SM8S12AHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM8S12AHM3/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 SM8S12AHM3/I?
For technical support, including SM8S12AHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM8S12AHM3/I requirements.
6.How does Aetrix verify that SM8S12AHM3/I is sourced from the original manufacturer or authorized distributors?
All SM8S12AHM3/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 SM8S12AHM3/I meets industry standards.
7.What is the process for return or replacement of SM8S12AHM3/I?
All SM8S12AHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SM8S12AHM3/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 SM8S12AHM3/I part is unused and in its original packaging.
Return procedure for SM8S12AHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM8S12AHM3/I Tags
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