My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SMCJ78-E3/9AT
- Part No.:
- SMCJ78-E3/9AT
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ78-E3/9AT.pdf
- Description:
- TVS DIODE 78VWM 139VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:5,626
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMCJ78-E3/9AT 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), 126 V clamping voltage (VC) at 11.9 A peak pulse current (IPPM), and 1500 W peak pulse power (PPPM) capability with AEC-Q101 qualification.
For engineers reviewing the SMCJ78-E3/9AT datasheet, SMCJ78-E3/9AT pinout, SMCJ78-E3/9AT application, or SMCJ78-E3/9AT equivalent, this device is selected for automotive power rail surge suppression, industrial sensor interface protection, and high-reliability DC bus clamping where fast response (<1 ns), low clamping ratio (VC/VWM ≈ 1.61), and MSL Level 1 solderability are critical.
Technical Context
The SMCJ78-E3/9AT operates as a silicon avalanche diode that enters controlled breakdown when reverse voltage exceeds its VBR range (86.7–95.8 V), limiting transient energy to safe levels via low incremental surge resistance. Its unidirectional polarity enables integration into DC-biased circuits without forward conduction during normal operation.
It delivers 1500 W peak pulse power under standardized 10/1000 µs waveform conditions, with thermal resistance RθJA = 75 °C/W and maximum junction temperature of 150 °C. The device is RoHS-compliant, meets UL 497B recognition, and is qualified to AEC-Q101 for automotive-grade reliability.
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 - Breakdown voltage range at 1 mA test current; defines turn-on threshold tolerance |
| VC @ IPPM | 126 V - Clamped voltage at 11.9 A peak pulse current; determines protected circuit's maximum transient stress |
| PPPM | 1500 W - Peak pulse power handling per 10/1000 µs waveform; defines surge energy absorption capacity |
| ID @ VWM | 1.0 µA - Reverse leakage at rated stand-off voltage; ensures minimal quiescent power loss |
| TJ max | +150 °C - Maximum junction temperature; supports operation in under-hood automotive environments |
| RθJA | 75 °C/W - Junction-to-ambient thermal resistance on standard 8 mm × 8 mm copper pads; guides heatsinking requirements |
Pinout & Package
Package: DO-214AB (SMCJ), surface-mount, low-profile, bi-directional leadframe variant with matte tin-plated leads compliant to J-STD-002 and JESD 22-B102. Cathode indicated by band marking on body.
| 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 | Reverse-biased clamping terminal | Connected to protected line (e.g., 78 V rail); clamps transients to cathode when voltage exceeds VBR |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive applications including engine control units and ADAS power supplies |
| MSL Level 1 rating | Enables direct placement without baking; peak reflow up to 260 °C per J-STD-020 |
| Glass passivated junction | Ensures stable VBR and low leakage over temperature and lifetime |
| Low clamping ratio (VC/VWM) | 1.61 - Minimizes overvoltage stress on downstream ICs during surge events |
| 1500 W PPPM rating | Supports IEC 61000-4-5 Level 4 (4 kV) surge immunity with margin |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface |
|---|---|
Use Scenario: Protecting 78 V battery-derived supply rails in commercial vehicle ECUs against load dump and inductive switching transients. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between rail and ground, absorbing >100 A surges within nanoseconds. Use Value: Prevents damage to voltage regulators and microcontrollers by limiting rail voltage to ≤126 V during 1500 W transients. | Use Scenario: Shielding analog input pins of precision ADCs in factory automation sensors exposed to ESD and cable discharge events. IC Role / Device Role / Timing Role: Front-end transient suppressor on 24–80 V sensor excitation lines, operating below VWM until fault occurs. Use Value: Maintains signal integrity with only 1.0 µA leakage at 78 V, while clamping 8 kV ESD pulses to safe levels. |
| Telecom DC Power Distribution | Renewable Energy Charge Controller |
Use Scenario: Safeguarding 48–96 V intermediate bus in telecom rectifier modules against lightning-induced surges on outdoor plant wiring. IC Role / Device Role / Timing Role: Primary overvoltage clamp on output stage, coordinated with upstream fuses and MOVs. Use Value: Delivers 1500 W pulse handling with <1 ns response, enabling compliance with ITU-T K.20/21 immunity standards. | Use Scenario: Protecting MOSFET gate drivers and shunt sense amplifiers in solar charge controllers operating from 72 V PV arrays. IC Role / Device Role / Timing Role: Bidirectional-capable unidirectional TVS used across isolated DC-DC feedback paths and high-side sensing nodes. Use Value: Withstands repeated 10/1000 µs surges up to 11.9 A without parameter drift, ensuring long-term field reliability. |
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), same VWM/VBR/VC specs | Suitable for space-constrained consumer electronics; insufficient for automotive load dump | Select SMCJ78-E3/9AT when 1500 W surge handling and AEC-Q101 are required |
| SMCJ78CA-E3/9AT | Bi-directional version; identical VWM/VBR/VC/PPPM but symmetric clamping in both polarities | Required for AC-coupled or floating signal lines; not usable on DC-biased rails without redesign | Choose SMCJ78-E3/9AT for unidirectional DC protection; use SMCJ78CA-E3/9AT only if bidirectional clamping is needed |
Compared with SMBJ78A-E3/52T and SMCJ78CA-E3/9AT, the SMCJ78-E3/9AT uniquely combines 1500 W surge capacity, AEC-Q101 qualification, and unidirectional polarity in the DO-214AB package-making it the only option among the three validated for under-hood automotive power rail protection.
Availability
SMCJ78-E3/9AT is available at Aetrix Electronics and suitable for automotive power systems, industrial sensor interfaces, telecom DC distribution, and renewable energy charge controllers requiring stable component supply and full traceability.
Supply support for SMCJ78-E3/9AT 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, TVS devices, and optoelectronics with emphasis on reliability and automotive qualification.
The SMCJ series is part of Vishay's TRANSZORB® family, engineered specifically for high-energy transient suppression in harsh environments-including automotive, industrial, and telecom infrastructure-where consistent clamping performance and long-term stability are mandatory.
FAQ
What is the clamping voltage of the SMCJ78-E3/9AT at its rated peak pulse current?
The SMCJ78-E3/9AT has a maximum clamping voltage (VC) of 126 V at its specified peak pulse current (IPPM) of 11.9 A under the standard 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 and ensures predictable overvoltage limiting for downstream components. The SMCJ78-E3/9AT maintains this clamping performance across its operating temperature range and after repeated surge events.
Is the SMCJ78-E3/9AT suitable for automotive applications?
Yes, the SMCJ78-E3/9AT is AEC-Q101 qualified and explicitly rated for automotive use, including engine control units, body electronics, and ADAS power supplies. Its DO-214AB package meets MSL Level 1, its junction temperature rating extends to +150 °C, and its 1500 W PPPM rating supports load dump immunity testing. The SMCJ78-E3/9AT is listed in Vishay's automotive-grade product portfolio with full PPAP documentation support.
How does the SMCJ78-E3/9AT differ from the bi-directional SMCJ78CA-E3/9AT?
The SMCJ78-E3/9AT is unidirectional and intended for DC-biased circuits, with polarity marked by a cathode band; the SMCJ78CA-E3/9AT is bi-directional and lacks polarity marking, enabling symmetric clamping on AC or floating lines. Both share identical VWM (78 V), VBR (86.7–95.8 V), VC (126 V), and PPPM (1500 W), but the SMCJ78-E3/9AT cannot replace the CA version in bidirectional applications without circuit redesign.
What is the maximum reverse leakage current of the SMCJ78-E3/9AT at its stand-off voltage?
The SMCJ78-E3/9AT exhibits a maximum reverse leakage current (ID) of 1.0 µA at its rated stand-off voltage (VWM) of 78 V and TA = 25 °C. This ultra-low leakage ensures negligible power loss in always-on systems and preserves accuracy in high-impedance sensor bias networks. Leakage remains below 5 µA up to TJ = 125 °C per Vishay's derating curves.
Does the SMCJ78-E3/9AT require heatsinking in typical applications?
The SMCJ78-E3/9AT is designed for operation without external heatsinking when mounted on the recommended 8.0 mm × 8.0 mm copper pads per terminal, achieving RθJA = 75 °C/W. In continuous power dissipation scenarios (e.g., repetitive surges), thermal simulation is advised-but for single-event transients per IEC 61000-4-5, no additional heatsink is required. The SMCJ78-E3/9AT's low thermal resistance enables reliable performance in compact automotive and industrial layouts.
SMCJ78-E3/9AT 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:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMCJ)
SMCJ78-E3/9AT FAQ
1.How can I place an order for SMCJ78-E3/9AT through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ78-E3/9AT 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 SMCJ78-E3/9AT reliable?
The price and inventory of SMCJ78-E3/9AT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ78-E3/9AT is usually 5 days.
3.What payment methods are accepted for SMCJ78-E3/9AT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ78-E3/9AT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ78-E3/9AT?
SMCJ78-E3/9AT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ78-E3/9AT 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 SMCJ78-E3/9AT?
For technical support, including SMCJ78-E3/9AT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ78-E3/9AT requirements.
6.How does Aetrix verify that SMCJ78-E3/9AT is sourced from the original manufacturer or authorized distributors?
All SMCJ78-E3/9AT 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 SMCJ78-E3/9AT meets industry standards.
7.What is the process for return or replacement of SMCJ78-E3/9AT?
All SMCJ78-E3/9AT units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ78-E3/9AT, 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 SMCJ78-E3/9AT part is unused and in its original packaging.
Return procedure for SMCJ78-E3/9AT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ78-E3/9AT Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
Comparator circuit design covering voltage thresholds, input limits, open-collector outputs, LM393 wiring, op-amp differences, hysteresis, timing, window detection and practical fault diagnosis.
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
