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Vishay General Semiconductor - Diodes Division SMCJ78-E3/57T
- Part No.:
- SMCJ78-E3/57T
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ78-E3/57T.pdf
- Description:
- TVS DIODE 78VWM 139VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:5,237
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Product details
Overview
SMCJ78-E3/57T from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in DO-214AB (SMCJ) package, designed for high-energy surge protection with 78 V stand-off voltage (VWM), 86.7–95.8 V breakdown voltage (VBR), 1500 W peak pulse power (PPPM), and 11.9 A peak pulse current (IPPM) at 10/1000 μs waveform. It protects MOSFETs, ICs, and sensor signal lines in automotive and industrial power supply rails.
For engineers reviewing the SMCJ78-E3/57T datasheet, SMCJ78-E3/57T pinout, SMCJ78-E3/57T application, or SMCJ78-E3/57T equivalent, key selection criteria include clamping voltage (VC = 126 V), thermal resistance (RθJA = 75 °C/W), AEC-Q101 qualification, RoHS compliance, and DO-214AB mechanical compatibility with automated SMT placement.
Technical Context
This TVS diode operates as a unidirectional clamping device, leveraging an avalanche breakdown mechanism to limit transient overvoltages before they damage downstream circuitry. Its glass-passivated junction ensures stable VBR tolerance (±5%) and low incremental surge resistance, critical for consistent clamping under repetitive surges.
Designed for surface-mount use on PCBs with 8.0 mm × 8.0 mm copper pads per terminal, it supports surge immunity per IEC 61000-4-5 (10/1000 μs) and meets UL 497B recognition. The E3 suffix confirms JESD 201 Class 1A whisker resistance and RoHS-compliant matte tin plating.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - Maximum continuous reverse operating voltage before clamping initiates |
| VBR min/max | 86.7 V / 95.8 V at IT = 1.0 mA - Ensures reliable avalanche conduction onset within tight tolerance |
| VC @ IPPM | 126 V at IPPM = 11.9 A - Clamped voltage during 10/1000 μs surge, defining protected circuit stress level |
| PPPM | 1500 W - Peak transient energy absorption capability under standardized waveform |
| TJ max | +150 °C - Enables operation in under-hood automotive environments and industrial enclosures |
| RθJA | 75 °C/W - Thermal resistance from junction to ambient, used to calculate temperature rise under DC bias |
| Package | DO-214AB (SMCJ) - Standardized surface-mount outline with cathode band marking and MSL Level 1 rating |
Pinout & Package
SMCJ78-E3/57T uses the DO-214AB (SMCJ) package: molded plastic case with gull-wing leads, 0.320" body length, 0.220–0.246" width, and cathode band marking on one end. Leads are matte tin-plated, solderable per J-STD-002 and JESD 22-B102.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side connection in unidirectional configuration | Connected to ground or low-impedance return path; current flows anode-to-cathode during clamping |
| Cathode | High-side connection; marked by band | Connected to protected line (e.g., 78 V rail); defines polarity-sensitive placement on PCB |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and surge endurance |
| Glass passivated junction | Improves long-term VBR stability and reduces parameter drift under thermal stress |
| MSL Level 1 (260 °C) | Enables standard reflow soldering without moisture-related popcorn failure |
| UL 497B recognized | Meets Underwriters Laboratories requirements for telecom and industrial surge protectors |
| JESD 201 Class 1A whisker resistance | Prevents tin whisker growth under thermal cycling, ensuring long-term solder joint integrity |
Applications
| Automotive Power Rail Protection | Industrial Sensor Signal Line Protection |
|---|---|
Use Scenario: Protecting 12 V/24 V battery-fed ECUs against load dump and alternator transients per ISO 7637-2. IC Role / Device Role / Timing Role: Unidirectional TVS placed between power rail and chassis ground to clamp surges above 78 V. Use Value: Limits clamped voltage to 126 V, preventing damage to 100 V-rated MOSFETs and microcontrollers in engine control modules. | Use Scenario: Shielding analog outputs of pressure/temperature sensors in factory automation PLC I/O modules. IC Role / Device Role / Timing Role: Low-capacitance TVS on 4–20 mA or 0–10 V signal paths to suppress ESD and inductive switching noise. Use Value: With <1 μA leakage at 78 V, avoids signal offset errors while providing 1500 W surge immunity per IEC 61000-4-5. |
| Telecom DC Power Input Protection | Computer PSU Overvoltage Clamp |
Use Scenario: Safeguarding PoE-powered equipment inputs against lightning-induced surges on 48 V DC lines. IC Role / Device Role / Timing Role: Primary-stage TVS on input side of DC-DC converter, coordinated with upstream fuses. Use Value: Fast response (<1 ns) and 126 V clamping ensure downstream DC-DC ICs (e.g., LM5017) remain below absolute maximum ratings. | Use Scenario: Secondary-side overvoltage protection in ATX PSUs where +12 V rail must not exceed 13.2 V under fault conditions. IC Role / Device Role / Timing Role: Standby clamping device across +12 V output, activated only during regulator failure or feedback loss. Use Value: 1500 W PPPM handles sustained overvoltage events longer than typical crowbar circuits, improving system robustness. |
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), smaller SMB package (DO-214AA), higher RθJA (110 °C/W) | Suitable for space-constrained consumer electronics; insufficient for automotive load dump | Select when board area is limited and surge energy does not exceed 600 W |
| SMCJ78AHE3/57T | Identical electrical specs but AEC-Q101 qualified (HE3 suffix), same DO-214AB package | Required for automotive OEM designs needing full qualification evidence | Choose for Tier 1 automotive programs requiring documented AEC-Q101 test reports |
Compared with SMCJ78-E3/57T, SMBJ78A-E3/52T trades surge capacity for footprint reduction, while SMCJ78AHE3/57T adds formal AEC-Q101 certification without altering performance-making it the drop-in qualified variant for automotive use.
Availability
SMCJ78-E3/57T is available at Aetrix Electronics and suitable for automotive power rail protection, industrial sensor interface design, and telecom DC input surge suppression requiring stable component supply across production lifecycles.
Supply support for SMCJ78-E3/57T 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 robustness against ISO 7637-2 and IEC 61000-4-5 surges is mandatory.
FAQ
What is the clamping voltage of SMCJ78-E3/57T under a 10/1000 μs surge?
The SMCJ78-E3/57T has a maximum clamping voltage (VC) of 126 V when subjected to its rated peak pulse current (IPPM = 11.9 A) using the 10/1000 μs waveform. This value is measured per ANSI/IEEE C62.35 and defines the upper voltage limit imposed on protected circuitry during transient events. The SMCJ78-E3/57T maintains this clamping performance across its specified operating temperature range.
Is SMCJ78-E3/57T suitable for automotive applications?
Yes, SMCJ78-E3/57T is suitable for automotive applications due to its AEC-Q101 qualification, 150 °C maximum junction temperature, and ability to withstand load dump transients per ISO 7637-2. Its glass-passivated junction and JESD 201 Class 1A whisker resistance further support under-hood reliability. Note that SMCJ78AHE3/57T is the fully documented AEC-Q101 variant if certification traceability is required.
What does the "E3/57T" suffix mean in SMCJ78-E3/57T?
The "E3" suffix indicates RoHS-compliant matte tin plating and JESD 201 Class 1A whisker resistance; "57T" denotes packaging in 7-inch diameter plastic tape and reel with 850 units per reel. This ordering code specifies both material compliance and logistics format-critical for SMT line setup and regulatory documentation. The SMCJ78-E3/57T is not AEC-Q101 qualified; that requires the HE3 suffix.
How does SMCJ78-E3/57T differ from bi-directional SMCJ78CA variants?
SMCJ78-E3/57T is unidirectional, with polarity marked by a cathode band and intended for DC line protection where reverse voltage is blocked. In contrast, SMCJ78CA is bi-directional, lacks polarity marking, and clamps surges of either polarity-used in AC-coupled or floating signal lines. Their VBR and VC values differ slightly; SMCJ78-E3/57T has VBR = 86.7–95.8 V, while SMCJ78CA has symmetric breakdown in both directions.
What PCB layout guidance applies to SMCJ78-E3/57T for optimal thermal performance?
For optimal thermal performance, mount SMCJ78-E3/57T on minimum 0.31" × 0.31" (8.0 mm × 8.0 mm) copper pads per terminal, as specified in the Vishay datasheet. Use internal or external copper planes connected via multiple vias to reduce RθJA. Avoid narrow traces between the device and ground/power planes. The SMCJ78-E3/57T's RθJA = 75 °C/W assumes this layout; deviation increases junction temperature and degrades surge endurance.
SMCJ78-E3/57T 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:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMCJ)
SMCJ78-E3/57T FAQ
1.How can I place an order for SMCJ78-E3/57T through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ78-E3/57T 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 SMCJ78-E3/57T reliable?
The price and inventory of SMCJ78-E3/57T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ78-E3/57T is usually 5 days.
3.What payment methods are accepted for SMCJ78-E3/57T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ78-E3/57T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ78-E3/57T?
SMCJ78-E3/57T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ78-E3/57T 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 SMCJ78-E3/57T?
For technical support, including SMCJ78-E3/57T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ78-E3/57T requirements.
6.How does Aetrix verify that SMCJ78-E3/57T is sourced from the original manufacturer or authorized distributors?
All SMCJ78-E3/57T 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 SMCJ78-E3/57T meets industry standards.
7.What is the process for return or replacement of SMCJ78-E3/57T?
All SMCJ78-E3/57T units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ78-E3/57T, 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 SMCJ78-E3/57T part is unused and in its original packaging.
Return procedure for SMCJ78-E3/57T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ78-E3/57T Tags
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