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Vishay General Semiconductor - Diodes Division SMC3K78CAHM3_A/H
- Part No.:
- SMC3K78CAHM3_A/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMC3K78CAHM3_A/H.pdf
- Description:
- 3KW, 78V 5%,BIDIR,SMC TVS
- Quantity:
- Payment:
- Shipping:
Inventory:1,500
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Product details
Overview
SMC3K78CAHM3_A from Vishay General Semiconductor is a bidirectional surface-mount Transient Voltage Suppressor (TVS) in SMC (DO-214AB) package, designed for high-energy surge protection with 3000 W peak pulse power (10/1000 μs), 126 V clamping voltage at 23.8 A, and 78 V stand-off voltage. It protects sensitive ICs, MOSFETs, and sensor signal lines in automotive power systems against ISO 7637-2 and ISO 16750-2 transients.
For engineers reviewing the SMC3K78CAHM3_A datasheet, SMC3K78CAHM3_A pinout, SMC3K78CAHM3_A application, or SMC3K78CAHM3_A equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification, 30 kV ESD immunity per IEC 61000-4-2, and compatibility with 12 V battery system load-dump and switching transient standards.
Technical Context
This TVS diode operates as a voltage-clamped shunt protector with fast response time and low incremental surge resistance. Its bidirectional architecture enables symmetric clamping above and below ground, supporting robust protection of differential or AC-coupled signal paths without polarity constraints.
It meets automotive-grade reliability requirements including AEC-Q101 qualification, MSL Level 1 moisture sensitivity, and UL 497B safety recognition. Thermal performance is characterized by RthJA = 90 °C/W and RthJM = 4.0 °C/W, enabling stable operation up to TJ = +175 °C in compact PCB layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VWM) | 78 V - Maximum continuous reverse operating voltage before clamping begins; defines safe operating margin for 12 V automotive systems. |
| Breakdown Voltage (VBR) | 86.7–95.8 V at 1 mA - Confirmed voltage threshold where device transitions into avalanche conduction under controlled test conditions. |
| Clamping Voltage (VC) | 126 V at 23.8 A (10/1000 μs) - Peak voltage seen across protected circuit during worst-case surge; critical for ensuring downstream component survival. |
| Peak Pulse Power (PPPM) | 3000 W (10/1000 μs) - Energy-handling capacity sufficient for ISO 7637-2 Pulse 1, 2a, 3a, 3b and ISO 16750-2 Pulse b events. |
| ESD Immunity | 30 kV contact & air discharge (IEC 61000-4-2) - Enables robust handling in manufacturing and field environments without additional ESD staging. |
| Operating Temperature | −55 °C to +175 °C - Supports under-hood automotive placement and industrial environments with wide thermal cycling. |
Pinout & Package
Package: SMC (DO-214AB), surface-mount, halogen-free, RoHS-compliant, AEC-Q101 qualified. Matte tin-plated leads, J-STD-002 solderable, JESD 201 Class 2 whisker tested. Polarity not marked on bidirectional types.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (K) | Anode-side terminal in unidirectional convention; functionally identical to Anode in bidirectional operation | Both terminals are electrically symmetric; no functional distinction - either lead may connect to line or ground in bidirectional clamp configuration. |
| Anode (A) | Cathode-side terminal in unidirectional convention; functionally identical to Cathode in bidirectional operation | Enables symmetrical clamping between two nodes (e.g., CAN_H/CAN_L, RS-485 A/B, or supply-to-ground), eliminating orientation dependency during placement. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Provides symmetrical overvoltage protection for AC signals, differential buses (e.g., CAN, LIN), and floating supply rails without polarity concerns. |
| AEC-Q101 qualification | Validated for automotive electronics use, including engine control units, body modules, and ADAS sensors requiring long-term reliability under thermal and vibration stress. |
| 3000 W peak pulse power | Handles severe load dump and inductive switching surges in 12 V systems per ISO 16750-2 Pulse b and ISO 7637-2 Pulse 1/2a/3a/3b without degradation. |
| Low clamping ratio (VC/VWM ≈ 1.61) | Minimizes voltage overshoot during transients, reducing stress on downstream 80 V-rated MOSFETs and 100 V-rated gate drivers. |
| MSL Level 1 rating | Allows unlimited floor life and reflow at 260 °C peak, simplifying SMT assembly without baking or special handling protocols. |
Applications
| Automotive Power Distribution | CAN Bus Protection |
|---|---|
|
Use Scenario: Protecting 12 V power rail inputs to ECUs, junction boxes, and lighting modules from alternator load dump and inductive kickback. IC Role / Device Role / Timing Role: Shunt-type transient suppressor placed directly at power entry point, clamping surges within nanoseconds before they propagate to regulators and microcontrollers. Use Value: Maintains <126 V clamping at 23.8 A, preventing latch-up or breakdown in 80 V input LDOs and PMICs during ISO 16750-2 Pulse b events. |
Use Scenario: Safeguarding high-speed CAN FD transceivers (e.g., TCAN1042, SN65HVD256) against ESD and bus faults in vehicle networks. IC Role / Device Role / Timing Role: Bidirectional TVS connected across CAN_H and CAN_L lines, absorbing common-mode and differential transients while preserving signal integrity. Use Value: Delivers 30 kV ESD immunity and sub-130 V clamping at 20 A, ensuring CAN communication remains uninterrupted during IEC 61000-4-2 contact discharge events. |
| Industrial Sensor Signal Conditioning | Telecom DC Power Input |
|
Use Scenario: Shielding analog front-end circuits (e.g., current-sense amplifiers, ADC references) in motor drives and PLC I/O modules from field-induced surges. IC Role / Device Role / Timing Role: Low-capacitance (<100 pF at 0 V) bidirectional clamp placed at sensor interface connector, limiting voltage excursions without distorting mV-level signals. Use Value: Clamps to ≤126 V within <1 ns, protecting 16-bit SAR ADCs and precision op-amps rated for ≤130 V absolute maximum input. |
Use Scenario: Securing −48 V DC telecom power inputs against lightning-induced surges and hot-swap transients in base station power supplies. IC Role / Device Role / Timing Role: Primary-stage TVS mounted at board edge, shunting energy before it reaches DC/DC converters and supervisory ICs. Use Value: Withstands 30 kW (8/20 μs) pulses per IEC 61000-4-5, enabling compliance with GR-1089-CORE Level 4 telecom surge immunity requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ78CA | Same VWM (78 V) and bidirectional structure, but lower PPPM = 600 W (SMB package); higher VC = 127 V at 12.1 A | Limited to lower-energy transients (e.g., IEC 61000-4-2 only); unsuitable for ISO 7637-2 Pulse 1 or load dump | Select when space-constrained layout prioritizes SMB footprint and surge energy is limited to ESD/EMI coupling. |
| SMCJ78CA | Identical SMC package and 3000 W rating, but non-AEC-Q101; VBR min/max tighter (86.7–93.1 V vs. 86.7–95.8 V) | Approved for industrial/commercial use only; lacks automotive qualification documentation and traceability | Choose for cost-sensitive non-automotive designs where AEC-Q101 is not mandated and full spec margin is acceptable. |
Compared with SMBJ78CA, SMC3K78CAHM3_A delivers 5× higher surge energy handling and automotive qualification; versus SMCJ78CA, it adds AEC-Q101 validation and extended VBR tolerance-critical for production consistency in Tier 1 automotive supply chains.
Availability
SMC3K78CAHM3_A is available at Aetrix Electronics and suitable for automotive ECUs, industrial sensor interfaces, telecom power inputs, and CAN/LIN bus nodes requiring stable component supply with guaranteed long-term manufacturability.
Supply support for SMC3K78CAHM3_A 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 SMC3KxxCAHM3_A series is part of Vishay's TRANSZORB® TVS platform, engineered specifically for AEC-Q101-compliant automotive transient suppression with enhanced surge robustness and zero orientation dependency.
FAQ
What is the clamping voltage of SMC3K78CAHM3_A at its rated peak pulse current?
The SMC3K78CAHM3_A clamps to 126 V at 23.8 A under the standard 10/1000 μs waveform. This value is measured and guaranteed per the Vishay datasheet (Document Number 98241, Rev. 09-Jan-2024), and represents the maximum voltage imposed on protected circuitry during worst-case surge events such as ISO 7637-2 Pulse 1. The SMC3K78CAHM3_A maintains this clamping performance across its full operating temperature range.
Is SMC3K78CAHM3_A qualified for automotive applications?
Yes, the SMC3K78CAHM3_A is AEC-Q101 qualified, as explicitly stated in the Vishay datasheet. It undergoes rigorous stress testing-including temperature cycling, humidity bias HAST, and mechanical shock-to meet automotive reliability standards. The "HM3_A" suffix denotes halogen-free, RoHS-compliant, and AEC-Q101-qualified construction, making the SMC3K78CAHM3_A suitable for under-hood and chassis-mounted modules in passenger and commercial vehicles.
Does SMC3K78CAHM3_A have polarity markings on the package?
No, the SMC3K78CAHM3_A does not feature polarity markings because it is a bidirectional TVS diode. Both terminals are functionally identical, allowing flexible PCB placement without orientation constraints. This eliminates assembly errors and simplifies layout for differential signal lines like CAN, LIN, or RS-485. The SMC3K78CAHM3_A's symmetry is confirmed in the "Mechanical Data" section of the Vishay datasheet.
What is the maximum junction temperature rating for SMC3K78CAHM3_A?
The SMC3K78CAHM3_A has a maximum junction temperature (TJ) rating of +175 °C, as specified in the "Maximum Ratings" table of the Vishay datasheet. This high thermal limit supports reliable operation in under-hood automotive environments and high-power industrial enclosures. Derating curves in Figure 2 confirm usable power dissipation down to ambient temperatures as low as −55 °C.
How does SMC3K78CAHM3_A perform under ISO 16750-2 Pulse b load dump conditions?
The SMC3K78CAHM3_A is validated for ISO 16750-2 Pulse b (load dump) in 12 V systems, clamping transients to ≤126 V while conducting up to 23.8 A. Its 3000 W peak pulse power rating ensures survivability across multiple pulses without parameter shift. Real-world test data in Figure 7 of the Vishay datasheet confirms stable clamping behavior after 5 pulses at 101 V, 150 ms duration - confirming suitability for alternator regulation failure scenarios.
SMC3K78CAHM3_A/H 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:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMC)
SMC3K78CAHM3_A/H FAQ
1.How can I place an order for SMC3K78CAHM3_A/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMC3K78CAHM3_A/H 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_A/H reliable?
The price and inventory of SMC3K78CAHM3_A/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMC3K78CAHM3_A/H is usually 5 days.
3.What payment methods are accepted for SMC3K78CAHM3_A/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMC3K78CAHM3_A/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMC3K78CAHM3_A/H?
SMC3K78CAHM3_A/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMC3K78CAHM3_A/H 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_A/H?
For technical support, including SMC3K78CAHM3_A/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMC3K78CAHM3_A/H requirements.
6.How does Aetrix verify that SMC3K78CAHM3_A/H is sourced from the original manufacturer or authorized distributors?
All SMC3K78CAHM3_A/H 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_A/H meets industry standards.
7.What is the process for return or replacement of SMC3K78CAHM3_A/H?
All SMC3K78CAHM3_A/H units undergo pre-shipment inspection (PSI). If there is an issue with SMC3K78CAHM3_A/H, 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_A/H part is unused and in its original packaging.
Return procedure for SMC3K78CAHM3_A/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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