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Vishay General Semiconductor - Diodes Division SM8S33CAHM3/I
- Part No.:
- SM8S33CAHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
SM8S33CAHM3/I.pdf
- Description:
- 6600 W BI-DIRECTIONAL TVS IS DO-
- Quantity:
- Payment:
- Shipping:
Inventory:1,639
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Product details
Overview
SM8S33CAHM3/I from Vishay General Semiconductor is a bidirectional surface-mount PAR® transient voltage suppressor (TVS) diode in DO-218AC package, designed for automotive load dump protection with 33 V standoff voltage (VWM), 38.7 V nominal breakdown (VBR), and 53.3 V clamping voltage (VC) at 124 A peak pulse current. It delivers 6600 W peak pulse power (10/1000 μs), operates up to 175 °C junction temperature, and is AEC-Q101 qualified.
For engineers reviewing the SM8S33CAHM3/I datasheet, SM8S33CAHM3/I pinout, SM8S33CAHM3/I application, or SM8S33CAHM3/I equivalent, this device is selected for high-reliability 12 V/24 V automotive power rail protection where ISO 7637-2 and ISO 16750-2 surge compliance, low leakage (<10 μA at VWM), and MSL Level 1 solderability are critical design requirements.
Technical Context
This TVS diode uses silicon avalanche junction technology optimized for fast response (<1 ns) to transient overvoltages induced by inductive switching or load dump events. Its bidirectional structure enables symmetrical clamping without polarity sensitivity, and its DO-218AC package integrates a metal heatsink terminal for low thermal resistance (RθJM = 0.35 °C/W).
The device meets AEC-Q101 stress test requirements including high-temperature operating life (HTOL), temperature cycling, and unbiased highly accelerated stress test (uHAST), confirming suitability for under-hood automotive environments where junction temperatures reach 175 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 33.0 V - Maximum continuous reverse operating voltage before clamping begins; defines safe operating window for 12 V/24 V automotive systems. |
| VBR (nom) | 38.7 V - Nominal breakdown voltage at 5 mA test current; ensures reliable turn-on during transients while avoiding false triggering. |
| VC @ IPPM | 53.3 V - Clamping voltage at 124 A peak pulse current (10/1000 μs); limits downstream IC voltage stress during ISO 7637-2 Pulse 5a events. |
| PPPM (10/1000 μs) | 6600 W - Peak pulse power handling capability; sustains high-energy surges without failure in automotive load dump scenarios. |
| TJ max | +175 °C - Maximum junction temperature rating; supports placement near hot engine control units without derating penalties. |
| ID @ VWM | <10 μA - Reverse leakage at 33 V and 25 °C; minimizes standby power loss in always-on vehicle modules. |
| Package | DO-218AC - Surface-mount package with metal heatsink terminal; provides low RθJM (0.35 °C/W) and meets UL 94 V-0 flammability. |
Pinout & Package
DO-218AC package features two terminals: Terminal 1 (anode/cathode-indifferent lead) and Terminal 2 (metal heatsink tab). The bidirectional design eliminates cathode marking; both terminals function identically under reverse or forward surge conditions. The metal tab serves as primary thermal path and must be soldered to a large copper pour for optimal thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Terminal 1 | Anode/Cathode (bidirectional) | Electrically symmetric terminal; connects to protected line (e.g., battery rail) with no polarity dependency. |
| Terminal 2 (Metal Tab) | Thermal Heatsink / Common Return | Primary thermal conduction path to PCB; must be soldered to ≥200 mm² copper area for rated RθJM = 0.35 °C/W. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood use via HTOL, temperature cycling, and uHAST testing per JESD22-A108. |
| ISO 7637-2 & ISO 16750-2 compliance | Meets Pulse 5a (load dump) and Pulse 1/2a (switching transients) requirements for 12 V/24 V systems. |
| MSL Level 1 rating | Reflow-compatible up to 245 °C peak without moisture-induced damage; eliminates bake requirement pre-assembly. |
| Halogen-free, RoHS-compliant construction | M3 suffix confirms lead-free matte tin plating, UL 94 V-0 molding compound, and JESD201 Class 2 whisker resistance. |
| 175 °C junction operation | Enables direct mounting on ECUs near heat sources without external thermal derating calculations. |
Applications
| Automotive Body Control Module (BCM) | Engine Control Unit (ECU) Power Input |
|---|---|
Use Scenario: Protecting BCM microcontroller supply rails from alternator load dump spikes during battery disconnect events. IC Role / Device Role / Timing Role: Bidirectional TVS clamping device placed between battery input and DC-DC converter input. Use Value: Limits transient voltage to ≤53.3 V during 6600 W surges, preventing latch-up or permanent damage to 3.3 V/5 V logic supplies downstream. | Use Scenario: Safeguarding ECU main 12 V input against inductive kickback from fuel injector or solenoid drivers. IC Role / Device Role / Timing Role: Primary overvoltage clamp on main power entry point, upstream of input filter capacitors. Use Value: Withstands 124 A peak pulses (10/1000 μs) while maintaining <10 μA leakage, preserving low-power sleep mode integrity. |
| ADAS Camera Power Supply | Infotainment Head Unit Battery Rail |
Use Scenario: Shielding high-speed image sensor power lines from ESD and conducted transients in rear-view camera modules. IC Role / Device Role / Timing Role: Secondary protection stage after fuse and common-mode choke, directly at sensor power pins. Use Value: Fast <1 ns response and 53.3 V clamping prevent pixel corruption or sensor reset during roadside ESD events. | Use Scenario: Securing infotainment system main battery connection against jump-start surges and alternator regulation faults. IC Role / Device Role / Timing Role: Front-end TVS on fused B+ input, coordinated with upstream polyfuse for overcurrent + overvoltage protection. Use Value: 6600 W peak power rating handles worst-case ISO 7637-2 Pulse 5a (110 V, 400 ms) without degradation over 1000+ cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33CA | Lower PPPM (400 W vs. 6600 W); DO-214AC package; no metal heatsink; RθJA = 60 °C/W. | Suitable only for low-energy transients (e.g., ESD, I/O lines); not rated for automotive load dump. | Select SMAJ33CA only for non-automotive, low-power signal-line protection where space constraints prohibit DO-218AC. |
| SM8S33A | Unidirectional version; same VWM/VBR/VC ratings but asymmetric clamping; requires correct polarity layout. | Used where circuit topology mandates unidirectional clamping (e.g., DC bias rails with defined ground reference). | Choose SM8S33A only when polarity is fixed and system grounding allows unidirectional protection; otherwise SM8S33CAHM3/I's bidirectional symmetry simplifies layout. |
Compared with SMAJ33CA and SM8S33A, the SM8S33CAHM3/I offers 16.5× higher surge power handling and true bidirectional operation in a thermally superior package-making it the sole choice for AEC-Q101-compliant automotive power rail protection requiring ISO 7637-2 Pulse 5a immunity.
Availability
SM8S33CAHM3/I is available at Aetrix Electronics and suitable for automotive body control modules, engine control units, ADAS camera systems, and infotainment head units requiring stable component supply across extended production lifecycles.
Supply support for SM8S33CAHM3/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 diodes, rectifiers, MOSFETs, and TVS devices with emphasis on automotive, industrial, and computing applications.
The SM8SxxCA family is engineered specifically for high-energy automotive transient suppression, targeting ISO 7637-2 load dump and ISO 16750-2 surge immunity in 12 V/24 V systems with AEC-Q101 reliability validation.
FAQ
What is the maximum clamping voltage of SM8S33CAHM3/I at its rated peak pulse current?
The SM8S33CAHM3/I has a maximum clamping voltage (VC) of 53.3 V at its rated peak pulse current (IPPM) of 124 A under the 10/1000 μs waveform. This value is measured per Figure 4 in the Vishay datasheet (Doc. #98229) and ensures downstream components remain within safe operating voltage limits during automotive load dump events. The SM8S33CAHM3/I maintains this clamping performance across its full operating temperature range.
Is SM8S33CAHM3/I suitable for 24 V commercial vehicle applications?
Yes, the SM8S33CAHM3/I is explicitly validated for 24 V commercial vehicle systems. Its 33 V stand-off voltage (VWM) provides adequate margin above nominal 24 V rails, and its 6600 W peak pulse power rating meets ISO 7637-2 Pulse 5a requirements for heavy-duty vehicles. The SM8S33CAHM3/I's AEC-Q101 qualification and 175 °C junction rating further confirm suitability for under-hood deployment in trucks and buses.
Does SM8S33CAHM3/I require a heatsink pad on the PCB?
Yes, the metal tab (Terminal 2) of the SM8S33CAHM3/I must be soldered to a dedicated thermal pad on the PCB. Vishay specifies a minimum copper area of 200 mm² for optimal thermal performance, achieving RθJM = 0.35 °C/W. Without this thermal pad, junction temperature rise exceeds specifications during repeated surge events, risking premature failure. The SM8S33CAHM3/I datasheet provides exact mounting pad dimensions in inches and millimeters.
How does the HM3 suffix affect SM8S33CAHM3/I's compliance status?
The HM3 suffix on SM8S33CAHM3/I indicates halogen-free, RoHS-compliant construction with matte tin-plated leads and JESD201 Class 2 whisker resistance. It also confirms AEC-Q101 qualification and MSL Level 1 rating (245 °C reflow peak). This suffix distinguishes it from non-HM3 variants that may lack automotive qualification or environmental compliance. All SM8S33CAHM3/I units meet these requirements as shipped.
Can SM8S33CAHM3/I replace older SM8S33A parts in existing designs?
Yes, the SM8S33CAHM3/I can replace unidirectional SM8S33A parts if the circuit layout accommodates bidirectional operation-no polarity marking is needed, and the DO-218AC footprint is identical. However, verify that system grounding allows symmetrical clamping; if the protected rail has strict DC polarity referencing, retain SM8S33A. The SM8S33CAHM3/I offers identical electrical specs plus enhanced thermal and reliability attributes.
SM8S33CAHM3/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):
- 33V
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 53.3V
- Current - Peak Pulse (10/1000µs):
- 124A
- 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-218AB
SM8S33CAHM3/I FAQ
1.How can I place an order for SM8S33CAHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SM8S33CAHM3/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 SM8S33CAHM3/I reliable?
The price and inventory of SM8S33CAHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM8S33CAHM3/I is usually 5 days.
3.What payment methods are accepted for SM8S33CAHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM8S33CAHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM8S33CAHM3/I?
SM8S33CAHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM8S33CAHM3/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 SM8S33CAHM3/I?
For technical support, including SM8S33CAHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM8S33CAHM3/I requirements.
6.How does Aetrix verify that SM8S33CAHM3/I is sourced from the original manufacturer or authorized distributors?
All SM8S33CAHM3/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 SM8S33CAHM3/I meets industry standards.
7.What is the process for return or replacement of SM8S33CAHM3/I?
All SM8S33CAHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SM8S33CAHM3/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 SM8S33CAHM3/I part is unused and in its original packaging.
Return procedure for SM8S33CAHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM8S33CAHM3/I Tags
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