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Vishay General Semiconductor - Diodes Division SM8S28AHM3/I
- Part No.:
- SM8S28AHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AC
- Datasheet:
-
SM8S28AHM3/I.pdf
- Description:
- TVS DIODE 28VWM 45.4VC DO218AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,892
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Product details
Overview
SM8S28AHM3/I from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor in DO-218AB package, rated for 28 V stand-off voltage (VWM), 32.8 V nominal breakdown (VBR), 6600 W peak pulse power (10/1000 μs), and AEC-Q101 qualified for automotive load dump protection.
For engineers reviewing the SM8S28AHM3/I datasheet, SM8S28AHM3/I pinout, SM8S28AHM3/I application, or SM8S28AHM3/I equivalent, this page delivers verified electrical parameters, thermal performance at TJ = 175 °C, ISO7637-2 compliance status, and direct alternative part guidance for high-reliability 12 V/24 V automotive power rail designs.
Technical Context
The SM8S28AHM3/I employs passivated anisotropic rectifier technology to achieve low leakage (<10 μA at VWM) and low forward voltage drop (VF ≤ 1.8 V @ 100 A), enabling robust clamping during load dump transients. Its DO-218AB package provides RθJM = 0.35 °C/W for efficient heatsink coupling, supporting sustained operation up to TJ = 175 °C.
It meets MSL Level 1 per J-STD-020 (245 °C peak reflow), features matte tin-plated leads solderable per J-STD-002/JESD22-B102, and is RoHS-compliant with HE3 suffix meeting JESD201 Class 2 whisker test requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 28 V - Maximum continuous reverse operating voltage before clamping begins; sets system-level overvoltage trip threshold for 24 V automotive rails. |
| VBR (min/typ/max) | 31.1 / 32.8 / 34.4 V @ 5 mA - Confirmed breakdown range ensures reliable turn-on during fast transients without premature conduction. |
| VC @ IPPM | 45.4 V @ 145 A (10/1000 μs) - Clamping voltage defines worst-case voltage seen by protected downstream ICs during surge events. |
| PPPM (10/1000 μs) | 6600 W - Peak surge energy handling capacity validated per ISO7637-2 Pulse 5a/b for automotive load dump immunity. |
| TJ max | 175 °C - Enables under-hood deployment in engine control units and body electronics without derating. |
| ID @ VWM | ≤10 μA @ 25 °C - Low leakage preserves battery standby current in always-on vehicle modules. |
| RθJM | 0.35 °C/W - Thermal resistance from junction to metal heatsink enables effective thermal management using PCB copper pour or external heatsink. |
Pinout & Package
Package: DO-218AB - Surface-mount, anode-heatsink configuration with molded UL 94 V-0 compound; cathode marked on top surface; designed for high-power dissipation with metal heatsink terminal.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Heatsink) | Power return path and thermal interface | Electrically connected to internal die cathode; must be soldered to large copper area or external heatsink for RθJM = 0.35 °C/W performance. |
| Cathode | Transient voltage clamp output | Connected to protected line (e.g., battery rail); conducts surge current to anode/heatsink when V > VBR. |
Key Features
| Feature | Design Value |
|---|---|
| Junction passivation | Optimized anisotropic rectifier process ensures stable VBR over lifetime and temperature, critical for AEC-Q101 reliability validation. |
| AEC-Q101 qualification | Validated for automotive-grade stress testing including HTGB, HTRB, and temperature cycling - required for ECU and ADAS module use. |
| ISO7637-2 compliance | Meets Pulse 5a (load dump) and Pulse 5b (clamped load dump) waveforms - directly supports OEM-level EMC certification. |
| MSL Level 1 rating | Supports standard SMT reflow profiles up to 245 °C peak without moisture-induced failure - eliminates pre-bake requirement. |
| Low VF (≤1.8 V @ 100 A) | Minimizes forward conduction loss during bidirectional surge events, reducing self-heating and improving clamping consistency. |
Applications
| Engine Control Unit (ECU) Power Input Protection | Body Control Module (BCM) Battery Rail Clamp |
|---|---|
Use Scenario: Protects microcontroller, CAN transceivers, and sensor interfaces from 12 V system load dump transients exceeding 40 V and lasting up to 400 ms. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between battery rail and input filter capacitor, clamping within 1 ns of overvoltage onset. Use Value: Limits peak rail voltage to ≤45.4 V during 6600 W surges, preventing latch-up or permanent damage to 3.3 V/5 V logic supplies. | Use Scenario: Shields LIN transceivers, door lock actuators, and lighting drivers from alternator-induced spikes during ignition and accessory switching. IC Role / Device Role / Timing Role: Primary overvoltage clamp on fused 12 V supply line upstream of DC-DC converters and LDOs. Use Value: Maintains <10 μA leakage at 28 V to avoid battery drain in sleep mode while delivering 145 A peak surge current capability. |
| Advanced Driver Assistance Systems (ADAS) Camera Power Supply | Electric Power Steering (EPS) Motor Controller Protection |
Use Scenario: Safeguards image sensor and ISP power domains against transients generated by nearby high-current solenoids and relays in front-end camera modules. IC Role / Device Role / Timing Role: Fast-response TVS placed immediately after input connector, before bulk capacitance and EMI filter. Use Value: Achieves 45.4 V clamping at 145 A ensures downstream 1.8 V/2.8 V analog and digital rails remain within absolute maximum ratings. | Use Scenario: Protects gate drivers and MCU power supplies from inductive kickback during motor phase commutation and emergency stop events. IC Role / Device Role / Timing Role: High-energy TVS mounted directly to heatsink on motor controller PCB, shunting surge current away from sensitive logic. Use Value: Leverages RθJM = 0.35 °C/W and TJ = 175 °C rating to sustain repeated 10/1000 μs surges without thermal runaway. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SM8S28AHM3 | Same electrical specs and DO-218AB package; differs only in packaging - no tape/reel (bulk) vs. I = 13" reel with anode orientation. | No functional difference; identical placement, soldering, and thermal behavior on PCB. | Select SM8S28AHM3/I for automated SMT assembly requiring indexed tape; choose SM8S28AHM3 for manual prototyping or low-volume hand-soldering. |
| SMAJ28AHE3_A/H | Lower PPPM (400 W), smaller SMA package (RθJA = 65 °C/W), same VWM/VBR but lower surge current (32.4 A). | Not suitable for load dump; limited to ESD and minor switching transients in non-automotive or low-power modules. | Use SMAJ28AHE3_A/H only where space constraints prohibit DO-218AB and surge energy is <500 W; not a drop-in replacement for SM8S28AHM3/I. |
Compared with SM8S28AHM3/I, SM8S28AHM3 offers identical protection performance with packaging flexibility, while SMAJ28AHE3_A/H trades 94 % lower surge capacity for 60 % smaller footprint - making SM8S28AHM3/I the sole choice for ISO7637-2-compliant automotive power rail protection.
Availability
SM8S28AHM3/I is available at Aetrix Electronics and suitable for automotive engine control units, body control modules, ADAS camera systems, and electric power steering controllers requiring stable component supply across extended temperature and high-surge environments.
Supply support for SM8S28AHM3/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 SM8SxxA family was engineered specifically for AEC-Q101-compliant automotive load dump protection, combining high-temperature junction stability (175 °C), ultra-low leakage, and industry-leading 6600 W surge capability in the DO-218AB package.
FAQ
What is the clamping voltage of SM8S28AHM3/I at its rated peak pulse current?
The SM8S28AHM3/I has a maximum clamping voltage (VC) of 45.4 V when subjected to its rated peak pulse current of 145 A under the standard 10/1000 μs waveform. This value is measured per JEDEC test conditions and defines the upper voltage limit imposed on protected circuitry during surge events. The SM8S28AHM3/I maintains this clamping performance consistently across its operational temperature range due to its passivated junction design.
Is SM8S28AHM3/I qualified for automotive applications?
Yes, SM8S28AHM3/I is AEC-Q101 qualified and explicitly designed for automotive use, including engine control units and body electronics. It meets ISO7637-2 Pulse 5a/b for load dump immunity, operates reliably from –55 °C to +175 °C, and carries the HE3 suffix confirming JESD201 Class 2 whisker resistance and RoHS compliance. The SM8S28AHM3/I datasheet documents full qualification test results per AEC-Q101 Rev G.
What does the "I" suffix mean in SM8S28AHM3/I?
The "I" suffix in SM8S28AHM3/I denotes the preferred packaging option: 13-inch diameter plastic tape and reel with anode oriented toward the sprocket hole, containing 750 units per reel. This format is optimized for high-speed pick-and-place SMT assembly. The base part SM8S28AHM3 is functionally identical but supplied in bulk; both share identical electrical, thermal, and reliability specifications.
Can SM8S28AHM3/I replace older SM8S28A variants?
Yes, SM8S28AHM3/I replaces legacy SM8S28A variants with enhanced manufacturing controls and AEC-Q101 qualification. It retains identical VWM (28 V), VBR (31.1–34.4 V), and PPPM (6600 W) ratings, but adds MSL Level 1 reflow compatibility, improved whisker resistance (HE3), and tighter process control. Designers may migrate to SM8S28AHM3/I without layout or schematic changes, as the DO-218AB footprint and pinout are unchanged.
What is the thermal resistance from junction to heatsink for SM8S28AHM3/I?
The SM8S28AHM3/I has a typical junction-to-mount (heatsink) thermal resistance (RθJM) of 0.35 °C/W when properly soldered to a copper heatsink or large PCB copper pour. This low value enables efficient heat transfer from the silicon die to the external thermal mass, supporting continuous operation at TJ = 175 °C. The SM8S28AHM3/I datasheet specifies this parameter per JEDEC 51-14 using the Transient Dual Interface Method (TDIM).
SM8S28AHM3/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):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.4V
- Current - Peak Pulse (10/1000µs):
- 145A
- 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
SM8S28AHM3/I FAQ
1.How can I place an order for SM8S28AHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SM8S28AHM3/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 SM8S28AHM3/I reliable?
The price and inventory of SM8S28AHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM8S28AHM3/I is usually 5 days.
3.What payment methods are accepted for SM8S28AHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM8S28AHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM8S28AHM3/I?
SM8S28AHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM8S28AHM3/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 SM8S28AHM3/I?
For technical support, including SM8S28AHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM8S28AHM3/I requirements.
6.How does Aetrix verify that SM8S28AHM3/I is sourced from the original manufacturer or authorized distributors?
All SM8S28AHM3/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 SM8S28AHM3/I meets industry standards.
7.What is the process for return or replacement of SM8S28AHM3/I?
All SM8S28AHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SM8S28AHM3/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 SM8S28AHM3/I part is unused and in its original packaging.
Return procedure for SM8S28AHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM8S28AHM3/I Tags
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