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Vishay General Semiconductor - Diodes Division SMC3K78CAHM3/9A
- Part No.:
- SMC3K78CAHM3/9A
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMC3K78CAHM3/9A.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:8,775
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Product details
Overview
SMC3K78CAHM3/9A from Vishay General Semiconductor is a bidirectional surface-mount TRANSZORB® transient voltage suppressor (TVS) in SMC (DO-214AB) package, rated for 3000 W peak pulse power (10/1000 μs), 78 V stand-off voltage (VWM), 86.7–95.8 V breakdown voltage (VBR), and 23.8 A peak pulse current (IPPM). It provides clamping protection for automotive sensor signal lines and industrial MOSFET gate drivers.
For engineers reviewing the SMC3K78CAHM3/9A datasheet, SMC3K78CAHM3/9A pinout, SMC3K78CAHM3/9A application, or SMC3K78CAHM3/9A equivalent, key selection criteria include bidirectional polarity, AEC-Q101 qualification, 150 °C max junction temperature, UL 497B safety recognition, and compatibility with wave-soldering constraints excluding bottom-side PCB mounting.
Technical Context
The SMC3K78CAHM3/9A operates as a voltage-clamping TVS diode with low incremental surge resistance and sub-nanosecond response time, designed to shunt transient energy away from sensitive downstream components. Its bidirectional structure enables symmetrical clamping across both polarities without external circuitry.
It meets J-STD-020 MSL Level 1 moisture sensitivity and JESD 201 Class 2 whisker resistance requirements, with matte tin-plated terminals solderable per J-STD-002 and JESD 22-B102. The device is halogen-free, RoHS-compliant, and qualified to AEC-Q101 for automotive use.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC/AC signal line operating margin. |
| VBR min/max | 86.7 V / 95.8 V - Breakdown occurs within this range at 1 mA test current; ensures predictable turn-on under transients. |
| VC @ IPPM | 126 V - Clamped voltage at 23.8 A peak pulse current; determines maximum stress imposed on protected IC or MOSFET. |
| PPPM | 3000 W - Peak pulse power handling capability with 10/1000 μs waveform; supports high-energy surge events like load dump or ESD. |
| TJ max | +150 °C - Maximum junction temperature rating; enables operation in under-hood automotive environments and industrial enclosures. |
| Polarity | Bidirectional - Provides symmetrical overvoltage protection for AC-coupled or floating signal paths without polarity biasing. |
| Package | SMC (DO-214AB) - Standardized surface-mount outline with 8.0 mm × 8.0 mm copper pad area recommendation for thermal dissipation. |
Pinout & Package
SMC3K78CAHM3/9A uses the SMC (DO-214AB) package: molded plastic case with two coplanar leads, UL 94 V-0 flammability rating, and matte tin-plated terminals. No polarity marking on bidirectional variants.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Anode) | Transient current return path | Both terminals are electrically symmetric; either lead serves as current entry/exit depending on transient polarity. |
| Anode (Cathode) | Transient current return path | Identical function to opposite terminal; no functional distinction due to bidirectional construction. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive-grade reliability including temperature cycling, HTRB, and surge endurance per JEDEC standards. |
| UL 497B recognition | Approved for primary and secondary circuit protection in telecom and industrial equipment per safety file E136766. |
| MSL Level 1 | Zero floor life limitation; can be stored indefinitely at ≤30 °C/85 % RH without baking prior to reflow. |
| Low incremental surge resistance | Minimizes voltage overshoot during fast-rising transients (e.g., ISO 7637-2 Pulse 1/2a), improving clamping fidelity. |
| Halogen-free & RoHS | Complies with environmental regulations for automotive and industrial end-equipment without compromising surge robustness. |
Applications
| Automotive Sensor Protection | Industrial Motor Drive Gate Protection |
|---|---|
Use Scenario: Protecting CAN/LIN bus transceivers and analog sensor outputs (e.g., pressure, temperature) from load-dump and inductive switching transients in engine control units. IC Role / Device Role / Timing Role: Voltage-clamping TVS placed directly at connector interface or IC input pins to limit transient excursions below absolute maximum ratings. Use Value: Prevents latch-up or permanent damage to 5 V or 3.3 V sensor signal chains while maintaining signal integrity during 10/1000 μs surges up to 3000 W. |
Use Scenario: Safeguarding IGBT/MOSFET gate drivers in variable-frequency drives from Miller-induced voltage spikes and cross-talk during high-dI/dt switching. IC Role / Device Role / Timing Role: Fast-response shunt device placed between gate and source to clamp gate-source voltage to ≤126 V during transient events. Use Value: Avoids unintended turn-on or gate oxide rupture by limiting VGS excursion beyond ±20 V tolerance of modern SiC and silicon power devices. |
| Telecom Line Interface Protection | Consumer Power Supply Input Protection |
Use Scenario: Shielding Ethernet PHYs, DSL line drivers, and PoE injectors from lightning-induced surges and AC mains coupling in outdoor network equipment. IC Role / Device Role / Timing Role: Primary-level surge suppression on differential pairs or DC bias rails upstream of isolation transformers or common-mode chokes. Use Value: Withstands repeated 6 kV/3 kA surges per IEC 61000-4-5 while maintaining <2 μA leakage at 78 V, minimizing standby power loss. |
Use Scenario: Securing AC-DC adapter inputs and USB-C PD controller supply rails against ESD and hot-plug transients in smart home hubs and portable chargers. IC Role / Device Role / Timing Role: Secondary-stage TVS after fuse and MOV, providing precise clamping where low VWM and tight VBR tolerance are critical. Use Value: Enables compact design with 78 V VWM matching 24 V system rails, reducing need for oversized capacitors or additional regulation stages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMC3K75CAHM3/9A | Lower VWM (75 V) and VBR (83.3–92.1 V); 121 V clamping at 24.8 A IPPM. | Suitable where tighter voltage margin is needed near 75 V nominal rail; slightly lower clamping stress on protected circuit. | Select when system operating voltage is ≤75 V and lower VC improves margin against IC overvoltage limits. |
| SMC3K82CAHM3/9A | Higher VWM (82 V) and VBR (91.1–101 V); 131 V clamping at 22.8 A IPPM. | Better immunity to nuisance tripping on 80 V systems; trades clamping voltage for higher standoff headroom. | Choose for 80 V battery systems or applications requiring higher VWM to avoid leakage-related power loss at elevated temperatures. |
Compared with SMC3K78CAHM3/9A, SMC3K75CAHM3/9A offers lower clamping voltage but reduced standoff margin, while SMC3K82CAHM3/9A increases voltage headroom at the cost of higher clamped stress-selection depends on whether system priority is transient suppression fidelity or operating voltage stability.
Availability
SMC3K78CAHM3/9A is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial motor drive gate circuits, and telecom line protection requiring stable component supply and long-term lifecycle support.
Supply support for SMC3K78CAHM3/9A 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 protection devices with emphasis on reliability, efficiency, and application-specific optimization.
The SMC3KxxCAHM3 series belongs to Vishay's AEC-Q101-qualified TRANSZORB® TVS family, engineered for robust transient suppression in harsh automotive and industrial environments where failure modes must be rigorously controlled.
FAQ
What does the "HM3" suffix indicate in SMC3K78CAHM3/9A?
The HM3 suffix in SMC3K78CAHM3/9A denotes halogen-free, RoHS-compliant construction with AEC-Q101 qualification. It confirms compliance with automotive reliability standards including temperature cycling, high-temperature reverse bias, and surge endurance testing-distinct from the commercial-grade M3 variant.
Is SMC3K78CAHM3/9A suitable for bottom-side wave soldering?
No, SMC3K78CAHM3/9A is not recommended for PCB bottom-side wave mounting per Vishay documentation. Its thermal mass and package geometry risk insufficient solder joint formation or delamination; reflow soldering is the preferred assembly method for this device.
What is the maximum clamping voltage of SMC3K78CAHM3/9A under full-rated surge current?
The maximum clamping voltage of SMC3K78CAHM3/9A is 126 V at its rated peak pulse current of 23.8 A (10/1000 μs waveform). This value is measured per ANSI/IEEE C62.35 and defines the upper voltage limit imposed on protected circuitry during worst-case transient events.
Does SMC3K78CAHM3/9A have polarity markings on the package?
No, SMC3K78CAHM3/9A has no polarity markings because it is a bidirectional TVS diode. Both terminals are functionally identical, and the device clamps symmetrically for positive and negative transients-eliminating orientation concerns during placement.
How does SMC3K78CAHM3/9A differ from the non-HM3 version SMC3K78CAM3/9A?
SMC3K78CAHM3/9A is AEC-Q101 qualified and intended for automotive applications, whereas SMC3K78CAM3/9A is commercial grade without automotive qualification. Both share identical electrical specs and SMC package, but only the HM3 variant undergoes extended reliability testing per JESD22 and AEC stress profiles.
SMC3K78CAHM3/9A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AB, SMC
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 78V
- Voltage - Breakdown (Min):
- 86.7V
- Voltage - Clamping (Max) @ Ipp:
- 126V
- Current - Peak Pulse (10/1000µs):
- 23.8A
- Power - Peak Pulse:
- 3000W (3kW)
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMCJ)
SMC3K78CAHM3/9A FAQ
1.How can I place an order for SMC3K78CAHM3/9A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMC3K78CAHM3/9A 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 SMC3K78CAHM3/9A reliable?
The price and inventory of SMC3K78CAHM3/9A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMC3K78CAHM3/9A is usually 5 days.
3.What payment methods are accepted for SMC3K78CAHM3/9A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMC3K78CAHM3/9A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMC3K78CAHM3/9A?
SMC3K78CAHM3/9A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMC3K78CAHM3/9A 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 SMC3K78CAHM3/9A?
For technical support, including SMC3K78CAHM3/9A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMC3K78CAHM3/9A requirements.
6.How does Aetrix verify that SMC3K78CAHM3/9A is sourced from the original manufacturer or authorized distributors?
All SMC3K78CAHM3/9A 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 SMC3K78CAHM3/9A meets industry standards.
7.What is the process for return or replacement of SMC3K78CAHM3/9A?
All SMC3K78CAHM3/9A units undergo pre-shipment inspection (PSI). If there is an issue with SMC3K78CAHM3/9A, 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 SMC3K78CAHM3/9A part is unused and in its original packaging.
Return procedure for SMC3K78CAHM3/9A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMC3K78CAHM3/9A Tags
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