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Vishay General Semiconductor - Diodes Division SMBJ78A-E3/5B
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- Part No.:
- SMBJ78A-E3/5B
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ78A-E3/5B.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:4,430
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Product details
Overview
SMBJ78A-E3/5B from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in the SMB (DO-214AA) package, designed to protect sensitive electronics against voltage transients induced by inductive load switching and lightning surges. 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 4.8 A peak pulse current, and 600 W peak pulse power rating with a 10/1000 µs waveform.
For engineers reviewing the SMBJ78A-E3/5B datasheet, SMBJ78A-E3/5B pinout, SMBJ78A-E3/5B application, or SMBJ78A-E3/5B equivalent, this device is selected for robust overvoltage protection on DC power rails, MOSFET gate drivers, and industrial sensor signal lines where fast response (<1 ps), low clamping ratio (VC/VBR ≈ 1.32), and AEC-Q101-qualified reliability are required.
Technical Context
The SMBJ78A-E3/5B 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 performance under repetitive 10/1000 µs transients at 0.01% duty cycle.
Thermally, it exhibits RθJA = 100 °C/W and RθJL = 20 °C/W, supporting operation up to TJ = +150 °C. With IFSM = 100 A (8.3 ms half-sine), it withstands high-energy surges without degradation when mounted on 5.0 mm × 5.0 mm copper pads per terminal.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - Maximum continuous reverse operating voltage before conduction begins; defines safe DC rail margin for 72–80 V systems. |
| VBR @ IT = 1 mA | 86.7–95.8 V - Breakdown range ensuring reliable turn-on during transients while avoiding false triggering. |
| VC @ IPPM = 4.8 A | 126 V - Clamped voltage limiting downstream IC stress; clamping ratio of ~1.32 enables effective protection of 100 V-rated components. |
| PPPM | 600 W - Peak pulse power handling with 10/1000 µs waveform; supports IEC 61000-4-5 Level 4 surge immunity testing. |
| IFSM | 100 A - Non-repetitive forward surge current rating; sustains high-current inductive kickback without bond wire failure. |
| TJ max. | +150 °C - Junction temperature limit enabling use in under-hood automotive and industrial environments. |
| Package | SMB (DO-214AA) - Low-profile SMD outline (5.21 mm × 4.06 mm × 2.20 mm) compatible with automated pick-and-place and reflow. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, unidirectional polarity indicated by cathode band. Matte tin-plated leads meet J-STD-002 solderability and JESD 22-B102 whisker resistance Class 2.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry / Reverse voltage reference | Connected to system ground or lower-potential node; establishes reference for clamping action. |
| Cathode | Reverse voltage input / Clamping output | Connected to protected line (e.g., 78 V rail); conducts avalanche current to anode during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power (10/1000 µs) | Enables compliance with IEC 61000-4-5 surge immunity requirements for industrial and automotive power inputs. |
| Clamping voltage ≤126 V at 4.8 A | Provides 22% headroom below 150 V absolute maximum ratings of common 100 V MOSFETs and controllers. |
| Response time <1 ps | Protects nanosecond-scale logic and analog circuits before transient energy couples into sensitive nodes. |
| MSL Level 1 (260 °C peak) | Supports standard lead-free reflow profiles without moisture-induced popcorn failure or delamination. |
| RoHS-compliant, commercial grade (E3 suffix) | Meets global environmental regulations without halogen restrictions; suitable for consumer, telecom, and industrial end equipment. |
Applications
| Industrial Motor Drives | Automotive Body Control Modules |
|---|---|
|
Use Scenario: Protection of 72 V battery-fed H-bridge gate drivers against inductive flyback during PWM switching. IC Role / Device Role / Timing Role: Unidirectional TVS clamps reverse voltage spikes at MOSFET source/drain nodes to prevent gate oxide rupture. Use Value: Limits transient overshoot to ≤126 V, preserving 100 V-rated SiC MOSFETs and reducing need for oversized gate resistors. |
Use Scenario: Safeguarding LIN bus transceivers and microcontroller I/O pins connected to 12 V/24 V auxiliary power domains. IC Role / Device Role / Timing Role: Fast-acting shunt device that diverts ESD and load-dump energy away from signal conditioning circuitry. Use Value: Achieves <1 ns response and sub-130 V clamping, meeting ISO 10605 and ISO 7637-2 Pulse 5a requirements. |
| Telecom Power Feeds | Renewable Energy Inverters |
|
Use Scenario: Overvoltage suppression on -48 V DC distribution lines exposed to lightning-induced surges in outdoor base stations. IC Role / Device Role / Timing Role: Standoff-rated TVS placed upstream of DC/DC converters to absorb multi-kA transients before regulation stage. Use Value: Withstands 600 W pulses and maintains VC ≤126 V, preventing latch-up in isolated feedback optocouplers and error amplifiers. |
Use Scenario: Protection of photovoltaic string monitoring ICs and MPPT controller inputs subjected to grid-switching transients. IC Role / Device Role / Timing Role: Primary-level clamp on 70–90 V PV string outputs, coordinated with MOVs and gas discharge tubes in staged protection. Use Value: Provides precise 78 V standoff and low-leakage (<1 µA) to avoid measurement drift in high-impedance voltage dividers. |
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-M3/5B | Halogen-free, RoHS-compliant variant; identical electrical specs and SMB package. | No functional difference; selected where halogen-free material compliance is mandated (e.g., EU public infrastructure). | Choose M3/5B when halogen-free bill-of-materials is required; otherwise E3/5B offers standard commercial compliance. |
| SMCJ78A-E3/57 | Larger SMC (DO-214AB) package; same VWM, VBR, VC, but higher PPPM = 1500 W and IPPM = 12.1 A. | Used where higher surge energy (e.g., IEC 61000-4-5 Level 5) or thermal derating margin is needed. | Select SMCJ78A-E3/57 only if board layout allows larger footprint and system requires >600 W surge handling. |
Compared with SMBJ78A-E3/5B, the M3/5B alternative provides identical protection performance with halogen-free construction, while the SMCJ78A-E3/57 delivers 2.5× higher pulse power in a larger package-making the SMBJ78A-E3/5B optimal for space-constrained 600 W-class designs requiring commercial-grade compliance.
Availability
SMBJ78A-E3/5B is available at Aetrix Electronics and suitable for industrial motor drives, automotive body control modules, telecom power feeds, and renewable energy inverters requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for SMBJ78A-E3/5B 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, precision, and application-specific optimization.
The SMBJ series is engineered for high-energy transient suppression in harsh environments, targeting automotive, industrial, and telecom applications where fast response, stable clamping, and AEC-Q101 qualification matter.
FAQ
What is the maximum clamping voltage of SMBJ78A-E3/5B at its rated peak pulse current?
The SMBJ78A-E3/5B has a maximum clamping voltage (VC) of 126 V at its specified peak pulse current (IPPM) of 4.8 A, measured using the standardized 10/1000 µs waveform. This value is guaranteed across the full operating temperature range and ensures predictable protection behavior for downstream 100 V-rated components. The SMBJ78A-E3/5B achieves this with a low incremental surge resistance, minimizing voltage overshoot during fast-rising transients.
Is SMBJ78A-E3/5B suitable for automotive applications?
The SMBJ78A-E3/5B is RoHS-compliant and qualified to commercial temperature grade (–55 °C to +150 °C), but it is not AEC-Q101 qualified. For automotive applications requiring AEC-Q101 certification, the equivalent part is SMBJ78AHE3_B/I (with HE3 suffix). The SMBJ78A-E3/5B remains appropriate for non-safety-critical automotive subsystems such as infotainment power rails or lighting control where formal qualification is not mandated.
What does the "E3/5B" suffix indicate in SMBJ78A-E3/5B?
The "E3" suffix denotes RoHS-compliant, commercial-grade construction with matte tin-plated leads, while "5B" specifies packaging in 13-inch diameter plastic tape and reel with a base quantity of 3200 units. This configuration supports high-volume automated assembly and meets J-STD-002 solderability and JESD 22-B102 whisker resistance Class 2 requirements. The SMBJ78A-E3/5B is distinct from M3 (halogen-free) and HE3 (AEC-Q101) variants.
How does SMBJ78A-E3/5B compare to bidirectional TVS diodes like SMBJ78CA?
The SMBJ78A-E3/5B is unidirectional and intended for DC line protection where polarity is fixed, offering lower leakage (<1 µA at 78 V) and no symmetrical breakdown ambiguity. In contrast, SMBJ78CA is bidirectional with identical VWM and VBR in both directions, suited for AC or floating signal lines. The SMBJ78A-E3/5B cannot replace SMBJ78CA in AC-coupled applications due to its inherent polarity dependence and lack of reverse conduction capability.
What PCB layout considerations are critical for optimal performance of SMBJ78A-E3/5B?
For optimal thermal and electrical performance, the SMBJ78A-E3/5B must be mounted on minimum 5.0 mm × 5.0 mm copper pads per terminal to achieve rated 600 W pulse power and 100 °C/W thermal resistance. Trace inductance between the TVS and protected node should be minimized-ideally <2 mm-to preserve sub-nanosecond response. Avoid routing high-speed signals near the cathode-anode path, and ensure the ground return path is low-impedance to prevent voltage rise during clamping. The SMBJ78A-E3/5B relies on proper layout to deliver its specified VC and IPPM performance.
SMBJ78A-E3/5B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AA, SMB
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 78V
- Voltage - Breakdown (Min):
- 86.7V
- Voltage - Clamping (Max) @ Ipp:
- 126V
- Current - Peak Pulse (10/1000µs):
- 4.8A
- Power - Peak Pulse:
- 600W
- 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-214AA (SMBJ)
SMBJ78A-E3/5B FAQ
1.How can I place an order for SMBJ78A-E3/5B through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ78A-E3/5B 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 SMBJ78A-E3/5B reliable?
The price and inventory of SMBJ78A-E3/5B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ78A-E3/5B is usually 5 days.
3.What payment methods are accepted for SMBJ78A-E3/5B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ78A-E3/5B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ78A-E3/5B?
SMBJ78A-E3/5B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ78A-E3/5B 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 SMBJ78A-E3/5B?
For technical support, including SMBJ78A-E3/5B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ78A-E3/5B requirements.
6.How does Aetrix verify that SMBJ78A-E3/5B is sourced from the original manufacturer or authorized distributors?
All SMBJ78A-E3/5B 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 SMBJ78A-E3/5B meets industry standards.
7.What is the process for return or replacement of SMBJ78A-E3/5B?
All SMBJ78A-E3/5B units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ78A-E3/5B, 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 SMBJ78A-E3/5B part is unused and in its original packaging.
Return procedure for SMBJ78A-E3/5B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ78A-E3/5B Tags
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