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Vishay General Semiconductor - Diodes Division SM6S20AHM3/I
- Part No.:
- SM6S20AHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AC
- Datasheet:
-
SM6S20AHM3/I.pdf
- Description:
- TVS DIODE 20VWM 32.4VC DO218AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,162
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Product details
Overview
SM6S20AHM3/I from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor (TVS) designed for automotive load dump protection in 24 V systems. It features a 20 V stand-off voltage (VWM), 22.2–24.5 V breakdown range (VBR at 5 mA), 4600 W peak pulse power (10/1000 μs), 175 °C junction rating, and DO-218AB package with anode-heatsink polarity.
For engineers reviewing the SM6S20AHM3/I datasheet, SM6S20AHM3/I pinout, SM6S20AHM3/I application, or SM6S20AHM3/I equivalent, key selection criteria include its AEC-Q101 qualification, ISO7637-2 compliance for load dump transients, low leakage (<10 μA at VWM), and thermal robustness up to TJ = 175 °C in high-reliability automotive power rails.
Technical Context
This TVS diode uses passivated anisotropic rectifier technology optimized for high-temperature stability and surge immunity. Its unidirectional configuration provides clamping during positive-going transients only, with cathode as the signal terminal and metal heatsink as anode - critical for proper PCB layout and thermal management in engine control units.
The device delivers 142 A peak pulse current (IPPM) at 10/1000 μs with 32.4 V clamping voltage (VC), enabling effective suppression of 24 V system load dump events. Its RθJM = 0.45 °C/W ensures efficient heat transfer to the heatsink, supporting sustained operation under repeated surge conditions per ISO7637-2 Pulse 5a.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20 V - Maximum continuous reverse operating voltage before clamping begins; defines safe operating margin in 24 V automotive supply rails. |
| VBR (min/typ/max) | 22.2 / 23.4 / 24.5 V at 5 mA - Tight 5% tolerance ensures predictable turn-on behavior across temperature and production lots. |
| VC @ IPPM | 32.4 V - Clamping voltage at 142 A peak pulse; limits downstream IC stress during ISO7637-2 load dump events. |
| PPPM (10/1000 μs) | 4600 W - Peak surge power handling capacity; supports single-event energy absorption without failure. |
| TJ max. | 175 °C - Enables use in under-hood environments where ambient temperatures exceed 125 °C. |
| Polarity | Unidirectional - Cathode is signal terminal; anode is metal heatsink - dictates PCB mounting orientation and grounding strategy. |
| Package | DO-218AB - Surface-mount outline with integrated metal heatsink; requires specific pad layout per IPC-7351 for thermal and mechanical reliability. |
Pinout & Package
Package: DO-218AB - molded surface-mount case with exposed metal heatsink acting as the anode terminal. Molding compound meets UL 94 V-0; matte tin-plated leads are solderable per J-STD-002 and JESD 22-B102. Polarity: heatsink = anode, lead 1 = cathode.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Metal Heatsink) | High-current return path and thermal interface | Must be soldered to large copper pour or heatsink plane; serves as primary conduction and thermal dissipation path during surge events. |
| Cathode (Lead 1) | Signal input / protected line connection | Connected to the 24 V rail or sensitive node being protected; clamps to VC when voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and surge endurance - required for ECU, body control, and ADAS modules. |
| ISO7637-2 compliant | Meets Pulse 5a (load dump) requirements up to 35 V test level with 10 ms exponential waveform - enables direct integration into 24 V vehicle architectures. |
| Junction temp. rating: 175 °C | Supports placement near high-power components (e.g., DC/DC converters, motor drivers) without derating concerns in under-hood applications. |
| Low leakage: ≤10 μA at VWM | Minimizes standby power loss and avoids false triggering in always-on circuits such as CAN bus nodes or battery monitoring systems. |
| RθJM = 0.45 °C/W | Enables >90% of surge energy to be conducted directly to heatsink - reduces junction temperature rise by ~65 °C vs. RθJA-only cooling. |
Applications
| Automotive Load Dump Protection | 24 V Power Rail Transient Suppression |
|---|---|
Use Scenario: Protecting engine control unit (ECU) power inputs during alternator load dump events in commercial vehicles. IC Role / Device Role / Timing Role: Unidirectional TVS clamping device placed between battery rail and DC/DC input stage. Use Value: Limits transient voltage to ≤32.4 V at 142 A, preventing damage to downstream PMICs and microcontrollers rated for 36 V absolute maximum. |
Use Scenario: Safeguarding infotainment head unit power supply against switching transients from adjacent solenoid drivers. IC Role / Device Role / Timing Role: Fast-response overvoltage clamp on 24 V main input, activated within nanoseconds of overvoltage onset. Use Value: Withstands 4600 W surges while maintaining <10 μA leakage at 20 V - preserving low-power sleep mode integrity. |
| Industrial 24 V PLC I/O Protection | Heavy-Duty Vehicle Battery Management |
Use Scenario: Shielding programmable logic controller (PLC) digital input modules from inductive kickback in factory automation systems. IC Role / Device Role / Timing Role: Primary transient suppressor on 24 V field-side power bus feeding optocoupler inputs. Use Value: 175 °C rating allows operation in sealed enclosures with ambient temps up to 105 °C without thermal derating. |
Use Scenario: Securing battery management system (BMS) cell monitor ICs during jump-start or regenerative braking surges in electric trucks. IC Role / Device Role / Timing Role: High-energy clamping element on BMS main power rail, coordinated with upstream fusing. Use Value: 3600 W rating at 10/10,000 μs waveform matches long-tail energy profiles of heavy-vehicle electrical disturbances. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SM6S20AHM3 | No /I suffix - same electrical specs but non-RoHS-compliant termination (lead-based solder finish). | Not suitable for new designs targeting RoHS or automotive PPAP; identical thermal and surge performance. | Select SM6S20AHM3/I for RoHS-compliant, AEC-Q101-qualified production requiring Pb-free assembly. |
| SM6S22AHM3/I | Higher VWM (22 V) and VBR (24.4–26.9 V); 35.5 V clamping at 130 A IPPM. | Better margin for 24 V systems with higher nominal rail variation; lower surge current handling than SM6S20AHM3/I. | Choose SM6S22AHM3/I if system tolerances require ≥22 V stand-off or tighter clamping voltage consistency above 30 V. |
Compared with SM6S20AHM3/I, SM6S20AHM3 lacks RoHS compliance and SM6S22AHM3/I trades 142 A surge capacity for higher voltage margin - making SM6S20AHM3/I optimal for cost-sensitive, RoHS-mandated 24 V load dump protection where 32.4 V clamping is acceptable.
Availability
SM6S20AHM3/I is available at Aetrix Electronics and suitable for automotive ECUs, industrial 24 V PLCs, and heavy-duty vehicle BMS designs requiring stable component supply with full traceability and lifecycle support.
Supply support for SM6S20AHM3/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 SM6SxxA series was developed specifically for AEC-Q101-compliant transient suppression in 12 V and 24 V automotive power networks, emphasizing thermal resilience, surge robustness, and ISO7637-2 Pulse 5a compliance.
FAQ
What is the clamping voltage of the SM6S20AHM3/I at its rated peak pulse current?
The SM6S20AHM3/I has a maximum clamping voltage (VC) of 32.4 V at its peak pulse current (IPPM) of 142 A under the 10/1000 μs waveform. This value is measured at TC = 25 °C and defines the upper voltage limit imposed on protected circuitry during surge events. The SM6S20AHM3/I maintains this clamping performance across its full operating temperature range due to its low VBR temperature coefficient (0.085 %/°C).
Is the SM6S20AHM3/I suitable for 24 V automotive load dump protection per ISO7637-2?
Yes, the SM6S20AHM3/I is explicitly designed and tested to meet ISO7637-2 Pulse 5a (load dump) requirements for 24 V systems. Its 4600 W peak pulse power rating, 175 °C junction capability, and AEC-Q101 qualification confirm suitability for under-hood deployment. The SM6S20AHM3/I's 20 V VWM and 32.4 V VC provide appropriate margin between nominal rail voltage and clamping threshold in real-world vehicle environments.
What does the "/I" suffix indicate in SM6S20AHM3/I?
The "/I" suffix in SM6S20AHM3/I denotes packaging in 13-inch diameter plastic tape and reel, with anode oriented toward the sprocket hole - a standard delivery format for automated SMT assembly. It also confirms RoHS compliance and Pb-free termination (matte tin plating), distinguishing it from the non-RoHS SM6S20AHM3 variant. The SM6S20AHM3/I remains fully compatible with reflow profiles up to 245 °C peak per J-STD-020 MSL Level 1.
How is thermal management implemented for the SM6S20AHM3/I in high-power applications?
The SM6S20AHM3/I uses its metal heatsink (anode) as the primary thermal path, achieving RθJM = 0.45 °C/W when mounted to a sufficient copper area. Effective thermal design requires soldering the heatsink to a ≥100 mm² 2 oz. copper pad connected to internal ground or thermal planes. Unlike standard SMD diodes, the SM6S20AHM3/I relies on heatsink conduction-not ambient convection-so board layout must prioritize low-impedance thermal vias and minimal thermal resistance between the device and system heatsink.
Does the SM6S20AHM3/I have bidirectional or unidirectional polarity?
The SM6S20AHM3/I is strictly unidirectional, with cathode as the signal terminal and the metal heatsink serving as the anode. This configuration enables clamping only during positive-going transients on the cathode side - ideal for protecting 24 V supply rails. Reverse-bias operation beyond VWM will not conduct, and the device offers no protection against negative transients. For bidirectional protection, two SM6S20AHM3/I devices must be used in series opposition - though this is not recommended due to increased footprint and complexity.
SM6S20AHM3/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):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 32.4V
- Current - Peak Pulse (10/1000µs):
- 142A
- Power - Peak Pulse:
- 4600W (4.6kW)
- 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
SM6S20AHM3/I FAQ
1.How can I place an order for SM6S20AHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SM6S20AHM3/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 SM6S20AHM3/I reliable?
The price and inventory of SM6S20AHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM6S20AHM3/I is usually 5 days.
3.What payment methods are accepted for SM6S20AHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM6S20AHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM6S20AHM3/I?
SM6S20AHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM6S20AHM3/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 SM6S20AHM3/I?
For technical support, including SM6S20AHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM6S20AHM3/I requirements.
6.How does Aetrix verify that SM6S20AHM3/I is sourced from the original manufacturer or authorized distributors?
All SM6S20AHM3/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 SM6S20AHM3/I meets industry standards.
7.What is the process for return or replacement of SM6S20AHM3/I?
All SM6S20AHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SM6S20AHM3/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 SM6S20AHM3/I part is unused and in its original packaging.
Return procedure for SM6S20AHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM6S20AHM3/I Tags
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DESD3V3E1BL-7B
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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