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Vishay General Semiconductor - Diodes Division SMCJ78CAHM3/I
- Part No.:
- SMCJ78CAHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ78CAHM3/I.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:5,993
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Product details
Overview
SMCJ78CAHM3/I from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMC (DO-214AB) package, designed for high-energy surge protection of DC power rails and signal lines. It features a 78 V standoff voltage (VWM), 126 V maximum clamping voltage (VC) at 11.9 A peak pulse current (IPPM), and 1500 W peak pulse power (10/1000 µs waveform), commonly deployed in automotive power supply inputs and industrial sensor interfaces.
For engineers reviewing the SMCJ78CAHM3/I datasheet, SMCJ78CAHM3/I pinout, SMCJ78CAHM3/I application, or SMCJ78CAHM3/I equivalent, key selection criteria include bidirectional clamping symmetry, AEC-Q101 qualification for automotive use, halogen-free RoHS compliance (HM3 suffix), and thermal resistance (RθJA = 75 °C/W) under standard PCB pad layout.
Technical Context
This TVS diode operates as a voltage-clamped shunt protector with symmetrical breakdown behavior in both polarities due to its bidirectional construction. Its glass-passivated junction ensures stable leakage (<1.0 µA at VWM) and fast response time (<1 ns), enabling effective suppression of ESD, lightning-induced transients, and inductive switching spikes.
The device is rated for continuous operation from −55 °C to +150 °C junction temperature and meets MSL Level 1 per J-STD-020 with 260 °C reflow peak. Its SMC package supports automated placement and provides low incremental surge resistance, critical for maintaining clamping performance during repetitive surge events.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC operating margin. |
| VBR min/max | 86.7 V / 95.8 V at 1 mA - Confirmed breakdown threshold range; ensures predictable turn-on across production lot. |
| VC @ IPPM | 126 V at 11.9 A - Clamped voltage during 10/1000 µs surge; determines protected circuit's maximum transient stress. |
| PPPM | 1500 W - Peak pulse power handling capacity; enables robust protection against IEC 61000-4-5 Level 4 surges. |
| IPPM | 11.9 A - Peak surge current supported at rated clamping voltage; directly tied to PCB copper pad sizing (8.0 mm × 8.0 mm). |
| TJ max | +150 °C - Maximum junction temperature; supports operation in under-hood automotive environments. |
| RθJA | 75 °C/W - Thermal resistance junction-to-ambient on standard pads; informs derating above 25 °C ambient. |
Pinout & Package
Package: SMC (DO-214AB), surface-mount, halogen-free, RoHS-compliant, matte tin-plated leads. Bidirectional configuration has no polarity marking; terminals are symmetric anode/cathode pairs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Surge return path (bidirectional) | Provides low-impedance path to ground or rail during positive or negative transients. |
| Cathode | Surge return path (bidirectional) | Electrically identical to Anode in CA devices; forms symmetrical clamping junction with Anode. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per stress test plan. |
| Halogen-free (HM3) | Meets IEC 61249-2-21 and JEDEC JS709C requirements; eliminates brominated flame retardants in molding compound. |
| Low incremental surge resistance | Enables tighter clamping (VC − VBR = 39.3 V) and reduced energy dissipation in protected ICs. |
| MSL Level 1 | Supports lead-free reflow up to 260 °C peak without moisture-induced damage; no baking required pre-assembly. |
| Glass passivated junction | Ensures stable leakage current (<1.0 µA) and long-term parameter stability under thermal/humidity stress. |
Applications
| Automotive Power Input Protection | Industrial Sensor Signal Line Protection |
|---|---|
Use Scenario: Protecting 12 V/24 V battery-fed ECUs from load dump and alternator transients per ISO 7637-2 Pulse 5a. IC Role / Device Role / Timing Role: Shunt clamping element placed between power rail and ground, responding within <1 ns to limit voltage excursion. Use Value: Withstands 1500 W surges while clamping to ≤126 V, preventing damage to downstream PMICs and microcontrollers. | Use Scenario: Safeguarding analog outputs of pressure/temperature sensors connected to PLC I/O modules. IC Role / Device Role / Timing Role: Bidirectional voltage clamp on differential or single-ended signal lines exposed to field wiring noise. Use Value: Symmetrical clamping ensures equal protection against both positive and negative transients, preserving signal integrity. |
| Telecom DC Power Feeds | Consumer Appliance Motor Drive Inputs |
Use Scenario: Securing 48 V PoE-powered equipment inputs against induced surges from nearby AC mains or lightning coupling. IC Role / Device Role / Timing Role: Primary overvoltage clamp on input stage, coordinated with upstream fuses and secondary filtering. Use Value: 75 °C/W RθJA allows thermal design margin on standard FR4 with 8 mm² copper pads, avoiding derating below 85 °C ambient. | Use Scenario: Protecting H-bridge gate drivers in washing machine motor control boards from back-EMF spikes during commutation. IC Role / Device Role / Timing Role: Fast-acting shunt device across DC bus or driver supply pins to absorb inductive kickback energy. Use Value: 11.9 A IPPM rating matches typical MOSFET switching surge currents, eliminating need for oversized alternatives. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ78CAHE3/A | Same VWM/VC, but unqualified for automotive; RoHS-compliant (E3), not halogen-free. | Lacks AEC-Q101 validation; unsuitable for automotive production or harsh-environment industrial use. | Select when cost sensitivity outweighs automotive qualification and halogen-free requirement. |
| SMCJ78CA-E3/57T | Identical electrical specs and AEC-Q101 qualification; differs only in packaging (7" tape/reel vs. 13" tape/reel). | No functional difference; choice depends on SMT line feed mechanism and volume procurement needs. | Select for compatibility with existing 7" reel handling infrastructure or smaller batch builds. |
Compared with SMCJ78CAHM3/I, SMAJ78CAHE3/A sacrifices automotive reliability assurance and halogen-free compliance for lower cost, while SMCJ78CA-E3/57T offers identical performance in a different reel format-making HM3/I optimal for high-reliability, environmentally regulated automotive programs requiring full traceability and material compliance.
Availability
SMCJ78CAHM3/I is available at Aetrix Electronics and suitable for automotive electronics, industrial sensor systems, and telecom power supplies requiring stable component supply, AEC-Q101 validation, and halogen-free compliance.
Supply support for SMCJ78CAHM3/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 protection devices with emphasis on reliability, efficiency, and application-specific optimization.
The SMCJ series targets high-energy transient suppression in demanding environments; it was engineered specifically for automotive, industrial, and telecom applications where robustness, consistency, and regulatory compliance are mandatory.
FAQ
What does the "CA" suffix indicate in SMCJ78CAHM3/I?
The "CA" suffix denotes a bidirectional configuration: SMCJ78CAHM3/I clamps voltage symmetrically for both positive and negative transients, unlike unidirectional "A" variants that require correct polarity orientation. This makes SMCJ78CAHM3/I ideal for AC-coupled lines or DC rails where polarity reversal risk exists, such as in automotive sensor interfaces or telecom data lines.
Is SMCJ78CAHM3/I qualified for automotive applications?
Yes, SMCJ78CAHM3/I is AEC-Q101 qualified, verified through standardized stress tests including high-temperature reverse bias, temperature cycling, and ESD. The "HM3" suffix confirms halogen-free, RoHS-compliant construction meeting automotive material requirements-making SMCJ78CAHM3/I suitable for engine control units, body electronics, and ADAS subsystems.
How does the SMC (DO-214AB) package affect thermal performance of SMCJ78CAHM3/I?
The SMC package of SMCJ78CAHM3/I delivers RθJA = 75 °C/W on standard 8.0 mm × 8.0 mm copper pads per terminal. This thermal resistance enables reliable operation up to +125 °C ambient when derated per Fig. 2 of the datasheet. Larger pads or internal copper planes further reduce junction temperature, extending lifetime under repeated surge conditions.
What is the maximum clamping voltage of SMCJ78CAHM3/I and how is it measured?
The maximum clamping voltage of SMCJ78CAHM3/I is 126 V, measured at 11.9 A peak pulse current (IPPM) using a 10/1000 µs double-exponential surge waveform. This value represents worst-case voltage seen by downstream circuitry during a standardized surge event and is guaranteed across the full operating temperature range (−55 °C to +150 °C).
Can SMCJ78CAHM3/I replace older SMCJ78A variants in existing designs?
No-SMCJ78CAHM3/I is bidirectional, whereas SMCJ78A is unidirectional with cathode band marking. Direct replacement requires verifying circuit topology: if the original design relies on polarity-sensitive clamping (e.g., protecting only positive transients on a DC rail), substituting SMCJ78CAHM3/I introduces unnecessary conduction paths and may compromise protection. Always validate layout and schematic compatibility before substitution.
SMCJ78CAHM3/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AB, SMC
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- 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):
- 11.9A
- Power - Peak Pulse:
- 1500W (1.5kW)
- 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)
SMCJ78CAHM3/I FAQ
1.How can I place an order for SMCJ78CAHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ78CAHM3/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 SMCJ78CAHM3/I reliable?
The price and inventory of SMCJ78CAHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ78CAHM3/I is usually 5 days.
3.What payment methods are accepted for SMCJ78CAHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ78CAHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ78CAHM3/I?
SMCJ78CAHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ78CAHM3/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 SMCJ78CAHM3/I?
For technical support, including SMCJ78CAHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ78CAHM3/I requirements.
6.How does Aetrix verify that SMCJ78CAHM3/I is sourced from the original manufacturer or authorized distributors?
All SMCJ78CAHM3/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 SMCJ78CAHM3/I meets industry standards.
7.What is the process for return or replacement of SMCJ78CAHM3/I?
All SMCJ78CAHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ78CAHM3/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 SMCJ78CAHM3/I part is unused and in its original packaging.
Return procedure for SMCJ78CAHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ78CAHM3/I Tags
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