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Vishay General Semiconductor - Diodes Division SMCJ78CAHE3/9AT
- Part No.:
- SMCJ78CAHE3/9AT
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ78CAHE3/9AT.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:3,766
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Product details
Overview
SMCJ78CAHE3/9AT from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMC (DO-214AB) package, designed for high-energy surge protection with 78 V standoff voltage (VWM), 1500 W peak pulse power (PPPM), and clamping voltage of 126 V at 11.9 A IPPM. It protects MOSFETs, ICs, and sensor signal lines against inductive switching transients and lightning-induced surges in automotive and industrial power electronics.
For engineers reviewing the SMCJ78CAHE3/9AT datasheet, SMCJ78CAHE3/9AT pinout, SMCJ78CAHE3/9AT application, or SMCJ78CAHE3/9AT equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification, 126 V VC at rated IPPM, low thermal resistance (RθJL = 15 °C/W), and compatibility with automated SMT placement on 8.0 mm × 8.0 mm copper pads.
Technical Context
This TVS diode operates symmetrically in both directions due to its bidirectional construction, enabling protection of AC-coupled or differential signal paths without polarity concerns. Its glass-passivated junction ensures stable breakdown behavior and low leakage (<1.0 μA at VWM), while the low incremental surge resistance supports consistent clamping under repetitive 10/1000 μs transients.
The device is rated for TJ = -55 °C to +150 °C and meets MSL Level 1 per J-STD-020 with 260 °C peak reflow profile. Its AEC-Q101 qualification confirms suitability for automotive powertrain and body electronics where reliability under thermal cycling and mechanical stress is critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - maximum continuous reverse operating voltage before clamping begins |
| VBR min/max | 86.7 V / 95.8 V at IT = 1.0 mA - guaranteed breakdown range defining turn-on threshold |
| VC @ IPPM | 126 V at 11.9 A - clamped voltage during 10/1000 μs surge, limiting stress on downstream components |
| PPPM | 1500 W - peak transient energy absorption capacity under standardized waveform |
| RθJL | 15 °C/W - low junction-to-lead thermal resistance enables efficient heat transfer to PCB copper |
| TJ max | +150 °C - maximum junction temperature rating supporting operation in under-hood environments |
| ID @ VWM | ≤1.0 μA - ultra-low reverse leakage preserves signal integrity in high-impedance circuits |
Pinout & Package
Package: SMC (DO-214AB), surface-mount, bidirectional configuration with no polarity marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Anode) | Surge current return path | Both terminals are electrically symmetrical; either serves as current entry/exit depending on transient polarity |
| Anode (Cathode) | Surge current return path | Identical function to opposite terminal; no functional distinction in bidirectional mode |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC or differential lines without external polarity management |
| AEC-Q101 qualified | Validated for automotive applications including engine control units and ADAS power supplies |
| Low RθJL (15 °C/W) | Reduces thermal derating impact during repeated surge events on standard PCB layouts |
| Glass-passivated junction | Ensures long-term stability of VBR and low leakage across temperature and humidity stress |
| MSL Level 1 | Supports standard SMT reflow without moisture sensitivity handling requirements |
Applications
| Automotive Power Supply Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Protecting 12 V/24 V battery-fed ECUs from load dump and alternator ripple transients. IC Role / Device Role / Timing Role: Primary overvoltage clamp placed across input rails upstream of DC/DC converters. Use Value: Clamps 126 V surges within 1 ns, preventing damage to 40 V-rated buck controllers and ensuring ASIL-B compliance. | Use Scenario: Shielding analog outputs of pressure/temperature sensors connected to PLC I/O modules. IC Role / Device Role / Timing Role: Bidirectional shunt protector on ±10 V differential signal pairs exposed to ESD and cable discharge. Use Value: Symmetric 126 V clamping maintains signal fidelity while suppressing >1 kV contact ESD per IEC 61000-4-2. |
| Telecom Line Card Surge Suppression | Consumer Appliance Motor Drive Protection |
Use Scenario: Guarding Ethernet PHY power pins and bias rails in outdoor base station line cards. IC Role / Device Role / Timing Role: Secondary-level TVS after gas discharge tube (GDT), absorbing residual energy from lightning-induced surges. Use Value: 1500 W PPPM handles 10/1000 μs waveforms up to 11.9 A, reducing need for cascaded protection stages. | Use Scenario: Safeguarding gate drivers and microcontrollers in washing machine motor inverters. IC Role / Device Role / Timing Role: Rail-to-rail clamp across 300 V DC bus and logic supply domains during brush commutation spikes. Use Value: Withstands 200 A IFSM (unidirectional test basis), providing margin against inrush-related overstress during startup. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ78CA-E3/61T | Lower PPPM (400 W), smaller SMA package (DO-214AC), higher VC (127 V at 3.2 A) | Targeted for space-constrained consumer electronics, not automotive-grade | Select when board area is limited and surge energy is ≤400 W |
| SMCJ78AHE3/9AT | Unidirectional version; same VWM, VC, and PPPM but requires polarity-aware layout | Used where DC-biased rails demand asymmetric clamping (e.g., 5 V logic supply) | Choose only if circuit topology enforces defined polarity and cathode orientation can be maintained |
Compared with SMAJ78CA-E3/61T and SMCJ78AHE3/9AT, the SMCJ78CAHE3/9AT delivers higher surge robustness in an automotive-qualified bidirectional form factor, eliminating polarity constraints while maintaining compatibility with standard SMC footprint and thermal pad design rules.
Availability
SMCJ78CAHE3/9AT is available at Aetrix Electronics and suitable for automotive power systems, industrial sensor interfaces, telecom line cards, and appliance motor drives requiring stable component supply and AEC-Q101 assurance.
Supply support for SMCJ78CAHE3/9AT 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, and protection devices with emphasis on reliability and automotive qualification.
The SMCJ series targets high-energy transient suppression in harsh environments, with design focus on automotive, industrial, and telecom infrastructure where sustained surge immunity and long-term parametric stability are mandatory.
FAQ
What is the clamping voltage of the SMCJ78CAHE3/9AT at its rated peak pulse current?
The SMCJ78CAHE3/9AT has a maximum clamping voltage (VC) of 126 V at its rated peak pulse current (IPPM) of 11.9 A under the 10/1000 μs waveform condition. This value is measured per JEDEC standards and defines the upper voltage limit imposed on protected circuitry during a full-rated surge event. The SMCJ78CAHE3/9AT maintains this clamping performance across its operational temperature range.
Is the SMCJ78CAHE3/9AT suitable for automotive applications?
Yes, the SMCJ78CAHE3/9AT is AEC-Q101 qualified and explicitly designated for automotive use via the "HE3" suffix. It meets stringent requirements for temperature cycling, mechanical shock, and long-term reliability in powertrain, body control, and ADAS subsystems. The SMCJ78CAHE3/9AT's 150 °C maximum junction temperature and MSL Level 1 rating further confirm its readiness for under-hood deployment.
How does the bidirectional configuration of the SMCJ78CAHE3/9AT affect its circuit implementation?
The bidirectional configuration of the SMCJ78CAHE3/9AT eliminates polarity marking and allows placement across any two nodes subject to differential or AC-coupled transients - such as RS-485 buses, transformer-coupled power supplies, or dual-rail sensor outputs. Unlike unidirectional TVS diodes, the SMCJ78CAHE3/9AT provides identical clamping in both directions without requiring external diode pairing or orientation verification during assembly.
What is the thermal resistance from junction to lead (RθJL) for the SMCJ78CAHE3/9AT, and why does it matter?
The SMCJ78CAHE3/9AT has a typical junction-to-lead thermal resistance (RθJL) of 15 °C/W, measured per JEDEC standards. This low value enables rapid heat transfer from the silicon junction to the PCB copper pads, minimizing transient temperature rise during repetitive surges. For the SMCJ78CAHE3/9AT, this directly supports sustained operation at elevated ambient temperatures and reduces derating requirements in compact layouts.
Does the SMCJ78CAHE3/9AT require special PCB layout considerations compared to smaller TVS packages?
Yes - the SMCJ78CAHE3/9AT must be mounted on minimum 0.31" × 0.31" (8.0 mm × 8.0 mm) copper pads per terminal to achieve its rated 1500 W PPPM and thermal performance. Smaller pads cause excessive thermal impedance and premature failure under surge conditions. The SMCJ78CAHE3/9AT's DO-214AB outline also mandates ≥0.126" (3.20 mm) clearance between terminals and adjacent traces to prevent arcing during high-voltage transients.
SMCJ78CAHE3/9AT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AB, SMC
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- 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:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMCJ)
SMCJ78CAHE3/9AT FAQ
1.How can I place an order for SMCJ78CAHE3/9AT through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ78CAHE3/9AT 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 SMCJ78CAHE3/9AT reliable?
The price and inventory of SMCJ78CAHE3/9AT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ78CAHE3/9AT is usually 5 days.
3.What payment methods are accepted for SMCJ78CAHE3/9AT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ78CAHE3/9AT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ78CAHE3/9AT?
SMCJ78CAHE3/9AT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ78CAHE3/9AT 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 SMCJ78CAHE3/9AT?
For technical support, including SMCJ78CAHE3/9AT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ78CAHE3/9AT requirements.
6.How does Aetrix verify that SMCJ78CAHE3/9AT is sourced from the original manufacturer or authorized distributors?
All SMCJ78CAHE3/9AT 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 SMCJ78CAHE3/9AT meets industry standards.
7.What is the process for return or replacement of SMCJ78CAHE3/9AT?
All SMCJ78CAHE3/9AT units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ78CAHE3/9AT, 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 SMCJ78CAHE3/9AT part is unused and in its original packaging.
Return procedure for SMCJ78CAHE3/9AT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ78CAHE3/9AT Tags
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