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Vishay General Semiconductor - Diodes Division SMCJ78HE3/9AT
- Part No.:
- SMCJ78HE3/9AT
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ78HE3/9AT.pdf
- Description:
- TVS DIODE 78VWM 139VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:3,490
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Product details
Overview
SMCJ78HE3/9AT from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in DO-214AB (SMCJ) package, designed for robust overvoltage protection of DC power rails and signal lines. It features a 78 V stand-off voltage (VWM), 86.7–95.8 V breakdown voltage (VBR) at 1 mA, 126 V maximum clamping voltage (VC) at 11.9 A peak pulse current, and 1500 W peak pulse power rating with 10/1000 µs waveform. It is AEC-Q101 qualified and used in automotive power supply input stages.
For engineers reviewing the SMCJ78HE3/9AT datasheet, SMCJ78HE3/9AT pinout, SMCJ78HE3/9AT application, or SMCJ78HE3/9AT equivalent, key selection criteria include clamping performance under 10/1000 µs transients, junction temperature derating above 25 °C, RoHS-compliant AEC-Q101 qualification status, and compatibility with automated SMT placement on 8.0 mm × 8.0 mm copper pads.
Technical Context
The SMCJ78HE3/9AT operates as a unidirectional avalanche diode, conducting only when reverse voltage exceeds its breakdown threshold. Its glass-passivated junction ensures stable VBR tolerance (±5%) and low incremental surge resistance, enabling consistent clamping during repetitive ESD or load-dump events.
Thermal design relies on RθJA = 75 °C/W (typ.) and RθJL = 15 °C/W (typ.), with derating applied above TA = 25 °C per Figure 2. It meets J-STD-020 MSL Level 1 and supports peak forward surge current (IFSM) up to 200 A for 8.3 ms half-sine wave.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - Maximum continuous reverse operating voltage before conduction begins; defines safe DC rail margin. |
| VBR min/max | 86.7 V / 95.8 V at IT = 1 mA - Tight 5% tolerance ensures predictable turn-on across production lots. |
| VC @ IPPM | 126 V at 11.9 A - Clamping voltage under 10/1000 µs surge; determines protected circuit's maximum transient stress. |
| PPPM | 1500 W - Peak pulse power handling capability; validates suitability for ISO 7637-2 Pulse 5a/b load-dump suppression. |
| TJ max | +150 °C - Maximum junction temperature; enables operation in under-hood automotive environments. |
| Package | DO-214AB (SMCJ) - Surface-mount outline with J-bend leads; compatible with standard SMT reflow profiles. |
| Qualification | AEC-Q101 qualified - Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD. |
Pinout & Package
SMCJ78HE3/9AT uses the DO-214AB (SMCJ) package: molded plastic case with J-bend leads, matte tin-plated terminals solderable per J-STD-002, and polarity indicated by a cathode band on the body end.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., ground or return path) in unidirectional configuration. |
| Cathode (banded end) | Reverse-blocking / clamping terminal | Connected to protected line (e.g., 12 V battery rail); conducts during overvoltage to shunt energy to ground. |
Key Features
| Feature | Design Value |
|---|---|
| Low-profile DO-214AB package | Enables high-density PCB layout and compatibility with automated pick-and-place equipment. |
| Glass-passivated chip junction | Ensures stable electrical parameters over time and environmental stress, critical for automotive field life. |
| 1500 W peak pulse power (10/1000 µs) | Provides robust protection against severe transients such as ISO 7637-2 Load Dump (Pulse 5). |
| AEC-Q101 qualification | Validates reliability for automotive applications including engine control units, body electronics, and ADAS power supplies. |
| MSL Level 1, 260 °C peak reflow | Supports lead-free reflow assembly without moisture-induced damage or delamination. |
Applications
| Automotive Power Input Protection | Industrial DC Power Rail Clamp |
|---|---|
Use Scenario: Protecting 12 V battery-fed ECUs from load-dump transients (up to 60 V sustained + 100 V spikes) per ISO 7637-2. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and system ground to clamp surges before they reach downstream regulators and microcontrollers. Use Value: Limits peak voltage to ≤126 V during 11.9 A transients, preserving integrity of 36 V-rated input stages in automotive PMICs and CAN transceivers. |
Use Scenario: Safeguarding 48 V industrial PLC I/O modules against inductive switching spikes from solenoid drivers. IC Role / Device Role / Timing Role: Standoff-clamp device on 48 V DC bus, absorbing energy from L·di/dt events generated by relay coil de-energization. Use Value: Withstands 1500 W pulses and maintains <1 µA leakage at 78 V, ensuring minimal standby power loss while delivering fast (<1 ns) response to transients. |
| Telecom Line Interface Surge Suppression | Consumer Power Adapter Output Protection |
Use Scenario: Secondary-side protection on PoE-powered Ethernet switches exposed to lightning-induced surges on data lines. IC Role / Device Role / Timing Role: Unidirectional clamp on isolated 54 V DC output rails feeding PHY ICs and magnetics. Use Value: Clamps to 126 V within nanoseconds, preventing latch-up or gate oxide rupture in 65 nm Ethernet controllers rated for ≤130 V absolute maximum. |
Use Scenario: Overvoltage safeguard on 5 V/9 V/12 V USB-C PD adapter outputs against feedback loop failure or Zener regulator drift. IC Role / Device Role / Timing Role: Final-stage TVS between DC-DC output and connector, acting as fail-safe shunt when primary regulation fails. Use Value: Delivers 126 V clamping at 11.9 A with <100 nA leakage at 78 V, eliminating false triggering while guaranteeing shutdown before downstream USB port ICs exceed ratings. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ78A-E3/52T | Lower PPPM (600 W), SMB package (smaller footprint, higher RθJA = 110 °C/W) | Suitable for space-constrained consumer ports but insufficient for automotive load-dump duty cycles. | Select only where peak surge energy is ≤600 W and thermal mass is limited. |
| 1.5KE78A | Through-hole DO-201 package, same VWM/VBR/VC specs, higher IFSM (250 A), no AEC-Q101 qualification | Applicable in industrial bench equipment where manual assembly and higher surge margin are prioritized over automotive compliance. | Choose for prototyping or non-automotive production where board-level reliability testing replaces AEC-Q101 validation. |
Compared with SMCJ78HE3/9AT, SMBJ78A-E3/52T offers reduced surge capacity and thermal performance in a smaller package, while 1.5KE78A provides identical electrical specs in through-hole form without automotive qualification-making SMCJ78HE3/9AT the sole choice for volume AEC-Q101-compliant SMT designs requiring full 1500 W capability.
Availability
SMCJ78HE3/9AT is available at Aetrix Electronics and suitable for automotive ECU power inputs, industrial 48 V DC distribution systems, and telecom PoE interface protection requiring stable component supply and full AEC-Q101 traceability.
Supply support for SMCJ78HE3/9AT 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 automotive-grade qualification.
The SMCJ series was developed specifically for high-energy transient suppression in harsh environments, targeting ISO 7637-2 and IEC 61000-4-5 compliant automotive and industrial power systems.
FAQ
What is the clamping voltage of SMCJ78HE3/9AT under a 10/1000 µs surge?
The SMCJ78HE3/9AT has a maximum clamping voltage (VC) of 126 V at 11.9 A peak pulse current (IPPM) under the standardized 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 and defines the upper voltage limit imposed on protected circuits during surge events. The SMCJ78HE3/9AT achieves this clamping performance while maintaining low incremental surge resistance, ensuring repeatable protection behavior across temperature and lifetime.
Is SMCJ78HE3/9AT suitable for automotive applications?
Yes, SMCJ78HE3/9AT is AEC-Q101 qualified and explicitly rated for automotive use, including under-hood environments with operating junction temperatures up to +150 °C. Its DO-214AB package meets MSL Level 1, and its 1500 W peak pulse power rating satisfies ISO 7637-2 Pulse 5a/b load-dump requirements. The "HE3" suffix confirms AEC-Q101 qualification, distinguishing it from commercial-grade "E3" variants.
What does the "9AT" in SMCJ78HE3/9AT indicate?
The "9AT" suffix denotes the preferred packaging option: 13-inch diameter plastic tape and reel, containing 3500 units per reel. This format is optimized for high-volume SMT assembly lines using standard 13″ feeder systems. The base part SMCJ78HE3 remains electrically and thermally identical across all packaging variants-including "57T" (7″ reel, 850 units) and bare die or bulk options.
How does SMCJ78HE3/9AT differ from bi-directional SMCJ78CA variants?
The SMCJ78HE3/9AT is unidirectional, meaning it blocks forward current and clamps only in reverse bias-ideal for DC rail protection with defined polarity. In contrast, SMCJ78CA is bi-directional, providing symmetrical clamping for AC or floating signal lines. Their VBR, VWM, and VC values differ: SMCJ78CA has VWM = 78 V but VBR = 86.7–95.8 V in both directions and VC = 126 V at lower IPPM. The SMCJ78HE3/9AT cannot substitute for SMCJ78CA in AC-coupled applications.
What is the thermal resistance of SMCJ78HE3/9AT, and how does it affect layout?
The SMCJ78HE3/9AT has a typical junction-to-ambient thermal resistance (RθJA) of 75 °C/W when mounted on 0.31″ × 0.31″ (8.0 mm × 8.0 mm) copper pads per terminal. To maintain TJ ≤ 150 °C under 6.5 W steady-state dissipation, PCB layout must provide adequate copper area and minimize trace length to ground planes. Derating curves in Figure 2 require reducing allowable power by 0.8%/°C above TA = 25 °C-critical for under-hood deployments.
SMCJ78HE3/9AT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AB, SMC
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 78V
- Voltage - Breakdown (Min):
- 86.7V
- Voltage - Clamping (Max) @ Ipp:
- 139V
- Current - Peak Pulse (10/1000µs):
- 10.8A
- Power - Peak Pulse:
- 1500W (1.5kW)
- 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)
SMCJ78HE3/9AT FAQ
1.How can I place an order for SMCJ78HE3/9AT through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ78HE3/9AT 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 SMCJ78HE3/9AT reliable?
The price and inventory of SMCJ78HE3/9AT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ78HE3/9AT is usually 5 days.
3.What payment methods are accepted for SMCJ78HE3/9AT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ78HE3/9AT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ78HE3/9AT?
SMCJ78HE3/9AT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ78HE3/9AT 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 SMCJ78HE3/9AT?
For technical support, including SMCJ78HE3/9AT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ78HE3/9AT requirements.
6.How does Aetrix verify that SMCJ78HE3/9AT is sourced from the original manufacturer or authorized distributors?
All SMCJ78HE3/9AT 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 SMCJ78HE3/9AT meets industry standards.
7.What is the process for return or replacement of SMCJ78HE3/9AT?
All SMCJ78HE3/9AT units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ78HE3/9AT, 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 SMCJ78HE3/9AT part is unused and in its original packaging.
Return procedure for SMCJ78HE3/9AT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ78HE3/9AT Tags
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