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Vishay General Semiconductor - Diodes Division SMC3K78CAHM3/57
- Part No.:
- SMC3K78CAHM3/57
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMC3K78CAHM3/57.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:1,700
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Product details
Overview
SMC3K78CAHM3/57 from Vishay General Semiconductor is a bidirectional surface-mount Transient Voltage Suppressor (TVS) diode 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 I/O interfaces.
For engineers reviewing the SMC3K78CAHM3/57 datasheet, SMC3K78CAHM3/57 pinout, SMC3K78CAHM3/57 application, or SMC3K78CAHM3/57 equivalent, key selection criteria include bidirectional polarity, AEC-Q101 qualification, 150 °C max junction temperature, UL 497B recognition, and halogen-free RoHS-compliant construction with HM3 suffix.
Technical Context
The SMC3K78CAHM3/57 operates as a clamping-type TVS diode with avalanche breakdown mechanism, delivering fast response time (<1 ns) and low incremental surge resistance to limit transient overvoltages before they damage downstream ICs or MOSFETs. Its bidirectional configuration enables symmetric suppression of both positive and negative transients without polarity constraints.
Designed for high-energy surge environments, it sustains 3000 W peak pulse power under standardized 10/1000 μs waveform while maintaining clamping voltage ≤126 V at IPPM. Thermal derating begins above TA = 25 °C, with full operation guaranteed from –55 °C to +150 °C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - Maximum continuous reverse operating voltage before clamping initiates; defines safe working margin for 72 V nominal automotive systems. |
| VBR min/max | 86.7 V / 95.8 V - Breakdown voltage range at 1 mA test current; ensures reliable turn-on within defined tolerance band under production variation. |
| VC @ IPPM | 126 V - Clamping voltage at 23.8 A peak pulse current; determines maximum stress imposed on protected circuit during worst-case surge. |
| PPPM | 3000 W - Peak pulse power handling per 10/1000 μs waveform; supports robust protection against ISO 7637-2 Pulse 5a/b and IEC 61000-4-5 Level 4 surges. |
| TJ max | +150 °C - Maximum junction temperature rating; enables use in under-hood automotive locations and high-ambient industrial enclosures. |
| Polarity | Bidirectional - Symmetric clamping for AC-coupled or floating signal lines; eliminates need for polarity-aware layout or orientation checks. |
| Qualification | AEC-Q101 - Qualified for automotive-grade reliability including HTOL, temperature cycling, and ESD testing; suitable for safety-critical ECUs and ADAS sensors. |
Pinout & Package
Package: SMC (DO-214AB), surface-mount, molded plastic case with matte tin-plated leads compliant with J-STD-002 and JESD 22-B102 solderability standards. MSL level 1, LF peak 260 °C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked side) | Transient conduction path (anode-to-cathode during positive surge) | Not marked on bidirectional types; terminals are functionally identical - either end serves as anode or cathode depending on transient polarity. |
| Anode (unmarked side) | Transient conduction path (cathode-to-anode during negative surge) | No polarity marking required; device symmetry allows arbitrary PCB orientation during placement. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional polarity only | Enables universal placement on differential or floating signal paths without orientation dependency or external polarity logic. |
| 3000 W peak pulse power (10/1000 μs) | Supports high-energy transients common in automotive load-dump and inductive switching events without thermal runaway. |
| AEC-Q101 qualified | Validated for automotive electronics per stress test requirements, including 1000-cycle temperature cycling and 1000-hour HTOL at 150 °C. |
| UL 497B recognized (E136766) | Meets safety standards for telecom and industrial equipment surge protection components, enabling regulatory compliance without additional system-level certification. |
| Halogen-free, RoHS-compliant HM3 suffix | Guarantees material compliance with environmental directives and whisker resistance per JESD 201 Class 2 for long-term reliability in lead-free reflow processes. |
Applications
| Automotive Sensor Protection | Industrial PLC I/O Protection |
|---|---|
Use Scenario: Protecting CAN/LIN bus transceivers and analog sensor inputs (e.g., pressure, temperature) from load-dump and ESD events in engine control units. IC Role / Device Role: Primary clamping element placed directly at connector interface or IC input pins. Use Value: Limits transient voltage to ≤126 V during 3000 W surges, preventing latch-up or gate oxide damage in 5 V/12 V sensor front-ends. |
Use Scenario: Shielding digital input modules in programmable logic controllers from field-wiring induced surges in factory automation systems. IC Role / Device Role: First-line transient suppressor on 24 V DC input channels before optocoupler or Schmitt trigger conditioning stages. Use Value: Withstands repeated 10/1000 μs surges up to 23.8 A while maintaining stable VWM of 78 V, ensuring no false triggering during normal operation. |
| Telecom Line Interface | Consumer Power Adapter Feedback Loop |
Use Scenario: Safeguarding Ethernet PHY interface circuits and PoE-powered devices against lightning-induced surges on RJ45 ports. IC Role / Device Role: Bidirectional clamping device across differential pairs or between line and ground in secondary-side protection networks. Use Value: Symmetric clamping behavior ensures equal protection for both polarities of fast-rising transients, critical for full-duplex communication integrity. |
Use Scenario: Protecting optocoupler feedback paths in isolated AC/DC adapters from primary-side switching noise coupling into secondary-side regulation loops. IC Role / Device Role: Low-capacitance transient suppressor placed across TL431 reference input or phototransistor base-emitter junction. Use Value: Junction capacitance <100 pF (measured at 1 MHz, zero bias) avoids signal distortion or loop instability in high-frequency feedback paths. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMC3K75CAHM3/57 | Lower VWM (75 V), lower VBR (83.3–92.1 V), higher IPPM (24.8 A), same PPPM (3000 W) | Suitable where tighter clamping margin is needed below 78 V nominal rails, e.g., 72 V battery systems with tighter tolerance budgets | Select when system nominal voltage is ≤75 V and lower clamping voltage is prioritized over margin to 78 V threshold |
| SMC3K82CAHM3/57 | Higher VWM (82 V), higher VBR (91.1–101 V), lower IPPM (22.8 A), same PPPM (3000 W) | Used in 80 V+ auxiliary power domains or legacy telecom systems requiring higher standoff before clamping activation | Choose for applications needing >80 V continuous operation with headroom before transient conduction begins |
Compared with SMC3K75CAHM3/57 and SMC3K82CAHM3/57, the SMC3K78CAHM3/57 offers optimal balance for 78 V-rated automotive subsystems-delivering precise clamping alignment with 72 V nominal battery systems while retaining sufficient margin against overvoltage drift and temperature variation.
Availability
SMC3K78CAHM3/57 is available at Aetrix Electronics and suitable for automotive sensor protection, industrial PLC I/O hardening, and telecom line interface surge suppression requiring stable component supply and long-term lifecycle support.
Supply support for SMC3K78CAHM3/57 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 TRANSZORB® TVS family, engineered specifically for high-power transient suppression in automotive, industrial, and telecom infrastructure where AEC-Q101 qualification and UL safety recognition are mandatory.
FAQ
What is the clamping voltage of the SMC3K78CAHM3/57 at its rated peak pulse current?
The SMC3K78CAHM3/57 has a maximum clamping voltage (VC) of 126 V when subjected to its rated peak pulse current (IPPM) of 23.8 A under the standard 10/1000 μs waveform. This value is measured per ANSI/IEEE C62.35 and guarantees the upper voltage limit imposed on protected circuitry during worst-case surge events. The SMC3K78CAHM3/57 maintains this clamping performance across its full operating temperature range.
Is the SMC3K78CAHM3/57 suitable for automotive applications?
Yes, the SMC3K78CAHM3/57 is AEC-Q101 qualified and explicitly designed for automotive use, including engine control units, ADAS sensors, and body electronics. Its HM3 suffix confirms halogen-free, RoHS-compliant construction and JESD 201 Class 2 whisker resistance-critical for under-hood reliability. The SMC3K78CAHM3/57 also carries UL 497B recognition (file E136766), supporting safety compliance in automotive subsystems.
What does the "HM3" suffix indicate in SMC3K78CAHM3/57?
The "HM3" suffix in SMC3K78CAHM3/57 denotes halogen-free, RoHS-compliant construction with AEC-Q101 qualification and JESD 201 Class 2 whisker resistance. It distinguishes this grade from commercial "M3" variants and confirms suitability for automotive and high-reliability industrial applications. The SMC3K78CAHM3/57 meets MSL level 1 and supports lead-free reflow up to 260 °C peak temperature.
How does the SMC3K78CAHM3/57 differ from the older SMC3K78CA-M3/57?
The SMC3K78CAHM3/57 replaces the legacy SMC3K78CA-M3/57 with enhanced reliability qualifications: HM3 adds AEC-Q101 qualification, JESD 201 Class 2 whisker resistance, and UL 497B recognition-features absent in the M3 version. Both share identical electrical specs and SMC (DO-214AB) packaging, but the SMC3K78CAHM3/57 is designated for new designs requiring automotive-grade assurance.
What is the maximum operating temperature for the SMC3K78CAHM3/57?
The SMC3K78CAHM3/57 has a maximum junction temperature (TJ max) of +150 °C and operates across a full range of –55 °C to +150 °C. This rating enables deployment in high-ambient environments such as automotive engine compartments or industrial motor drives. Derating curves in the datasheet (Document Number 89433) define allowable power reduction above 25 °C ambient, ensuring thermal stability for the SMC3K78CAHM3/57 in real-world conditions.
SMC3K78CAHM3/57 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)
SMC3K78CAHM3/57 FAQ
1.How can I place an order for SMC3K78CAHM3/57 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMC3K78CAHM3/57 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 SMC3K78CAHM3/57 reliable?
The price and inventory of SMC3K78CAHM3/57 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMC3K78CAHM3/57 is usually 5 days.
3.What payment methods are accepted for SMC3K78CAHM3/57?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMC3K78CAHM3/57 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMC3K78CAHM3/57?
SMC3K78CAHM3/57 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMC3K78CAHM3/57 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 SMC3K78CAHM3/57?
For technical support, including SMC3K78CAHM3/57 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMC3K78CAHM3/57 requirements.
6.How does Aetrix verify that SMC3K78CAHM3/57 is sourced from the original manufacturer or authorized distributors?
All SMC3K78CAHM3/57 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 SMC3K78CAHM3/57 meets industry standards.
7.What is the process for return or replacement of SMC3K78CAHM3/57?
All SMC3K78CAHM3/57 units undergo pre-shipment inspection (PSI). If there is an issue with SMC3K78CAHM3/57, 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 SMC3K78CAHM3/57 part is unused and in its original packaging.
Return procedure for SMC3K78CAHM3/57:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMC3K78CAHM3/57 Tags
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